Popular Science Monthly/Volume 78/June 1911/The Vienna Institution for Experimental Biology
|THE VIENNA INSTITUTION FOR EXPERIMENTAL BIOLOGY|
By Professor CHARLES LINCOLN EDWARDS
COINCIDENT with the founding of our own government, the Emperor Joseph II., of Austria, opened to the public the Prater, the largest park in Vienna. At the entrance is the Prater-Stern, a street-car center directly accessible from all parts of the inner city and the outer districts by means of the city railway and many lines of electric cars. Here the people flock, especially on Sundays and holidays, to that part known as the Volks-Prater, which is a veritable Austrian Coney Island, with music, theaters, a giant wheel, circus, race-tracks, exhibits of natives from various lands and the attractive sights of "Venice in Vienna." On Easter Monday and May Day the largest and gayest throngs seek the Prater, where they visit the many forms of amusement, or walk and drive for miles through the park. Under the four rows of chestnut trees in the Haupt-allée the fashionable aristocrats parade in their fine equipages drawn by beautiful horses and bearing liveried coachmen and footmen.
The International Exhibition of 1873, located in the Prater, had an imposing aquarium constructed after plans by Brehm. More recently this structure has been used by the Zoological Society of Vienna as a vivarium for the display of the smaller animals. In consequence of the existence of an older zoological garden, the royal menagerie at Schönbrunn, it has not been possible to maintain this similar enterprise in Vienna. Following a suggestion of Professor Hatschek, Dr. Hans Przibram obtained the vivarium building from the zoological society in 1902 and joined with the botanists. Dr. Wilhelm Figdor and Leopold V. Portheim, in the establishment of an institution exclusively for scientific research which has already become renowned. The field is not limited, but offers an opportunity for the investigation of any biological problem, chiefly by means of experimentation, upon either plants or animals of the sea or the fresh waters, of the air, or the land, or dwelling in caves or burrows beneath the surface of the soil. The grounds, forming the garden around the vivarium building, were rented from the government for fifteen years. The main building (Fig. 1) had to be completely reconstructed and was then supplemented by two glass houses and various workshops and cages for the larger animals. The garden is screened from the passing throng by a vine-covered fence and a row of leafy shrubs and trees. As one enters the hall of the institution, he sees, on every hand, the preparations and specimens resulting from the experimental work so successfully carried on here. In the middle of the building are five parallel corridors, while to either side and in the rear are suites of rooms for manifold purposes.
The Vienna Institution for Experimental Biology includes zoological, botanical and physico-chemical sections. By virtue of an agreement
with the royal Austrian ministry of education the state assists the founders by maintaining two laboratory places in each of the zoological and botanical sections. The award of these tables, as well as the promotion of the general interests of the institution and its close affiliation with the university institutes, is vested in a board of curators consisting of the four professors of the biological subjects in the philosophical faculty of the University of Vienna. Thus far these curators have been Professors Wiesner, in botany (chairman), Grobben and Hatschek, in investigation of the fresh waters of Austria, which thus far has been established for the physico-chemical section which was organized in 1907, and this place is filled by the professors of the medical faculty. The ministry of agriculture has made an annual appropriation for the zoology, and v. Wettstein, in botany. A governmental table has been used for botanical researches under the direction of Professor v. Wettstein. The tables are free to students working under the supervision of the directors, but independent investigators pay an annual fee of 1,000 crowns. About fifty workers are here engaged in investigations each
year. At present the staff of the institution is as follows: zoological section, director. Dr. Przibram, assistants, Drs. Kammerer and Megušar; botanical section, directors, Dr. Figdor and Ritter v. Portheim,
assistants, Herr Fröschel and Herr Freund; physico-chemical section, director. Professor Pauli, assistant, Herr Schorr; fresh-water investigations, Herr Brunnthaler.
The Vienna institution differs from most of the preceding biological institutes in that here experimentation, carried on for long periods of time, even generation after generation, if necessary, and always under the best possible conditions, takes the place of research in descriptive and comparative anatomy, or the briefer experiments of physiology. In the study of experimental evolution one not only follows the organisms through ovulation, fertilization and embryogenesis, but the new generation must be raised to the adult stage for another breeding. The laws through which the external factors of existence influence the vitality can only be determined when it is possible for the organisms
experimented on to live under unchanging conditions for months or even years. Darwin acted upon these principles and his garden at Down must always rank as one of the greatest laboratories for experimental biology. It is only necessary to visit the zoological institute in Würzburg with its vivaria, series of basins and shaded pond, to realize, as one can from his writings, that Semper also was fully aware of the primary importance of experimentation in the solution of biological problems. Along with the foundation and growth of the Vienna institution has been that of the station for experimental evolution of the Carnegie Institution created and directed by Davenport, and the gardens developed by Ewart and Bateson in Great Britain. Similar establishments for the study of genetics have been advocated by Behla (1894), and more recently by Plate (1906) and Müller (1907). indeed, every biological laboratory is more or less permeated by this spirit of experimental investigation which the recent literature of biology shows may be successfully carried on even without elaborate equipment.
In keeping animals in confinement it is necessary not only to know their habitats, but also their manner of movement and whether they prefer light or darkness and living or dead food. For the investigations upon land animals carried on in the Vienna station, terraria have been constructed with especial care. The sloping bottom of the metal terrarium (Fig. 2) contains soil, with drainage for superfluous water and micro gas burners, or electric bulbs for heating. On one side of the
glazed superstructure and in the roof, ventilating screens are inserted. According to the degree of moisture needed the ground material varies from bran for meal-beetles and clothes-moths, sawdust for cockroaches, clay for bees, wasps and tiger-beetles, fine sand for leaf insects and rove-beetles and common garden soil for earthworms, glow-worms and wood-lice. Plants are used for the production of oxygen and food and with pieces of old bark and branches constitute a natural environment with its grateful shade and hiding places. To provide necessary moisture the ground is sprinkled in the early morning and during the day for the diurnal animals and in the evening for the nocturnal forms. Each day an artificial mist, or rain, is produced in the terrarium atmosphere by means of a hand atomizer or a small compression air pump. Meal-worms constitute the most useful general food. These larvæ are placed in small, oval, porcelain sugar-bowls which because of their concave sides, prevent escape. For different animals it is necessary to provide scraped meat, fresh ant pupae, earthworms, snails, flies, kitchen scraps, chopped fruit and vegetables, as well as any small animals available. Careful attention is given to cleaning the cages. The water basins are emptied by siphons and then sponged. The plants in pots and tufts of moss and turf are changed, stones and wood scoured with hot water and the upper layer of sand or earth renewed. Smaller vivaria are employed for special experiments. In these a double cover
of gauze provides an air space to ensure the circulation of air. The nests of social insects, like bumble bees and burrowing wasps, are transferred from their natural locations in the late evening when all of the family are at home. The insectaria are then placed in moss-covered ditches, or else buried in the earth, and in a few days the insects become quite contented.
In order to mitigate the conditions of confinement which unfavorably affect certain animals there are four large and many small outdoor terraria (Fig. 3).
There is a separate house (Fig. 4), bowed around the north side of the grounds, for heredity researches upon the higher vertebrates. Each of the sixteen cages has an outwardly-sloping cement floor, wire screen ventilators, heating pipes and electric lights, and opens into a garden plot having trees for the cats to climb in, basins in which swimming birds may disport themselves and soil surrounded with cement walls within which the wild rabbits may burrow. The kangaroos here find ample space in which to run about while snakes and lizards sun themselves on the rock-piles and turtles and frogs alternate between land and water.
The two glass houses (Fig. 5), one adapted for warmth and the other for cold, are in the south portion of the grounds. The glazed superstructure rests upon a thick wall and the floor lies one half a meter below the ground level. Each glass house is divided into a culture
room and a preparation room (Fig. 6), the latter being connected with the main building by a glass-covered passage-way. Each culture loom is provided with a water and sand bed and a water reservoir sunken in the floor. Electric light enables the experimenter to work continuously when necessary. Venetian curtains are used as a protection from excess of light or cold.
The middle corridor of the main building is covered with a double glass roof. One portion, used as a warm room, contains sweating boxes maintained at various temperatures. In the cold portion (Fig. 7) the conditions are favorable for the culture of fresh water and marine algae and the various organisms that grow in slime. The garden includes beds for the cultivation of plants for fodder and the experimental work. One large basin (Fig. 8), and four that are smaller, contain the higher water plants and algæ which grow during the warm season. In the shady, western part of the garden there are six cement basins (Fig. 9), especially for the rearing of plants, and at the same time serving as a home for the hosts of protozoa that wander in and can be used for investigations.
A station for experimental biology must have not only the proper equipment for breeding and rearing organisms under natural conditions, but also for artificially changing and controlling the external factors of the environment. The physico-chemical laboratory (Fig. 10) provides the substances used as variable external factors and also to determine the physico-chemical properties of the biologically important colloids.
These albuminous substances are placed in parchment paper sacks, in closed vessels or in moving water from which the carbon dioxid has been removed and thus for weeks and months are kept free from decay or carbon dioxid or other noxiousness of the laboratory air. A heliostat provides for the penetration of objects with the rays of sunlight and for the ultra-microscopic ends. A nephelometer is used for the estimation of cloudiness whereby errors in physiological observation due to the confounding of comparative and observation fluidities may be reduced. A dilatometer serves to determine the changes in volume and variations in water content of the biocolloids. Then there are pycnometers of all kinds for specific gravity computations and an Ostwald's viscosimeter, in a transparent thermostat, for the determination of the viscosity of colloid solutions. Especial value is placed upon electrical methods of investigating colloids. A proper distillation plant serves exclusively for providing the purest so-called conducting water. There is an apparatus after Kohlrausch with various electrode vessels for the estimation of the electric conductivity of electrolytes. For the determination of ion concentration in solutions there is a complete contrivance made of brass with electromotor power and having concentration chains with an elongated measuring bridge and a mirror galvanometer with reading telescope. The mechanisms for the calculation of the electric charge of colloids are technically perfected. The conducting apparatus of Landsteiner and Pauli was tested in an investigation
on toxins. Here each colloid, separated from the remaining fluid by the electric permeation, arises and can be easily isolated and tested. Since only the alternating current is found in the institution, two batteries, one of 200 and one of 75 volts, are employed to produce the current. In addition there are the necessary normal and precision thermometers, the instruments for the determination of the freezing point and the coagulation point, precision rheostats, Weston's volt- and ampere-meter, polarimeters and numerous small auxiliary apparatus.
The large general laboratory has fifteen working places fitted with all the usual optical and histological apparatus and reagents. The necessary conditions for the study of the influence of mechanical agencies are enough light, as little dust and infectious material as possible and sterilizing flames. One line of research is to subject organisms to the influence of different densities in the surrounding medium. For fluids there are basins containing different concentrations of salts, brackish water, etc., with an areometer for measuring the specific gravity of each of the various liquids. For gases there are hand air pumps and means of attachment to the supply pipes of the large electric air pump located in the cellar. For changing the normal influence of gravitation there are clinostats regulated by clockwork and centrifuges with contact plugs for tapping the electric power wherever needed.
Two dark rooms (Fig. 11) are fitted for studying the influence of light. Both open into a dark corridor from which a triangular door
leads into an anteroom lighted by a red dark-room light. The larger dark room serves for investigations upon the influence of definitely determined lights. Hung up at one end is an arc lamp in which different colored carbons can be used. The elongated form of the room makes possible experiments in which the organisms are placed at different distances from the light source. For investigating the influence of variously colored surroundings, small vivaria are placed in lighted rooms with colored glass covers for direct light, or colored wall coverings, for reflected light. A special apparatus has been constructed for the study of under and over lighting of fishes and amphibia (Fig. 12). For over lighting the aquarium is covered with an enclosing box open above (o) and for under lighting the box is closed above (u). For increasing the under light there are mirrors (s) at an angle of 45° beneath the aquaria. To dispense with these in over lighting a black paper is shoved under the aquarium. Cave animals and fungi are bred and observations made upon etiolated plants and regeneration against the exhalations of various crystals. Through a trap door iron steps descend into a dark vaulted cemented cellar room which is used as a cave. The air is saturated with moisture by water standing on the floor and the temperature is maintained at 12° C.
For all of the purposes of the institution a reliable heating plant is necessary. A central low pressure steam boiler furnishes rather constant
warmth for the main building, with a warm water system for the glass houses. Small thermostats, which can be exactly regulated, maintain the desired temperature of the different rooms. The northeast half of the building is kept at the ordinary room temperature (17° C.), while the southwest half is warmer and includes seven rooms. In a glazed compartment (Fig. 13) is the highest temperature (37° C.), next the portion of the same room separated by the glass partition (27° C.), then the warm glass house and the warm corridors for terraria and aquaria (20°-25° C.). A large basin is warmed in winter by a tinned tube kept at 10°-12° C.
The Vienna institution for experimental biology is a pioneer in the use of the carbonic-acid cooling machine for maintaining a cold environment so that different plants and animals can be observed during several generations at specified and perfectly controlled temperatures. Four rooms are kept at + 5° C, + 10° C, + 15° C. and + 20° C. The carbonic acid machine (Fig. 14) produces 5,500 calories hourly.
Fig. 12. Apparatus for Over and Under Lighting. d, compressed air; s, mirror; o, box, open above; p, box, open below; w, glass walls.
The fluid carbonic acid flows into a wrought-iron spiral core within a carefully isolated receptacle made of tin plate. The salt water surrounding the spiral core is cooled to a low temperature by the sudden
expansion of the liquid carbon dioxid. Then the carbonic acid gas is compressed under 55 atmospheres and conducted into a wrought-iron spiral core in the condenser where it is again cooled, liquefied and ready to flow on in the continuous circulation through the machine. The cold salt water is pumped through the extensive cast-iron radiators of the different cold rooms and the temperature regulators automatically open or shut the valve at the inflow of the cold salt water.
For many years it has been demonstrated, notably in the great Berlin aquarium, that marine animals and plants may be transported a long distance from their native habitats and then live on in aquaria with unimpaired health and growth. Hence it became an essential part of the plan to include marine organisms within the field of work of the institution and a complete equipment was installed for the investigation of problems of marine biology. Natural sea water, from the zoological
|Fig. 14. A. Carbonic-acid Cooling Machine with condenser, pumps for the compression of carbonic acid gas and for the circulation of the cooled salt water.|
|B. One of the Cold Rooms with the cast-iron radiators for the circulation of the cold salt water.|
station in Triest, is brought in car loads of thirty casks, each containing 500 liters. It is not difficult to maintain the proper concentration of salts and the same water can be used for years. It is not more expensive than artificial sea water, which is apt to vary in its constitution. Non-corrosive substances like glass, porcelain, glazed clay, cement, wood, hard rubber and lead lined with tin, were used in the construction of the aquaria for sea water. A plan of these aquaria, with the associated apparatus for aeration (Fig. 15), shows the distribution of sea water from the elevated reservoir (A), to cement basins (D), or to the smaller isolation jars in the next compartment. The effluent water, after being cleansed by running through the filter (H), is stored in the subterranean cistern (K), and thence driven by the sea-water pump (Fig. 16), up to the reservoir. The air pump (Fig. 16, Q), driven by an electric motor, forces air, which may be diluted by the attachment (P), or compressed to five atmospheres (R), into five tanks holding 455 liters (T), from which, by means of a reducing valve (U), it is allowed to escape under a pressure of from 1.1 to 1.2 of an atmosphere and is then distributed (V) to the aquaria. In the case of delicate animals, or eggs, solitary or in masses, the air must issue from the terminal plug in very fine bubbles. The outflow is through a plug of bamboo, or merely a piece of finely perforated rubber, while for the larger basins, charcoal or pumice is used. A natural plankton and bottom fauna develops, which is of interest
Fig. 15. Plan of the Sea-water Aquaria and the Aeration Equipment. A, reservoir; B, outlet pipe; C, ebonite cock; D, basin; E, F, removable outlet pipe and plug; G, outlet pipe; H, filter basin; K, cistern; L, riser pipe; M, pump; N, inlet pipe. Aeration Apparatus: O, inlet filter; P, attachment for air dilution; Q, air pump; R, attachment for air compression; S, manometer; T, air reservoir; U, reducing valve; V, conducting pipes; W, outlet; X, flexible connection; Y, glass tube; Z, excurrent perforated plugs.
as material for investigation and important as food for animals under experimentation. Such forms appear as small hydromedusæ, ctenophores, worms, ascidians and numerous copepods. Much additional food is required and for this chopped fish, or other meat, is used, but given in small quantities to avoid spoiling the water. Tunicates and mollusks like Nassa and Mytilus, placed in the larger aquaria, quickly remove the food débris. Protection from the sun is necessary to prevent an excess of green algae from obscuring the subjects of experimentation. In the small covered jars the proper concentration of salts is maintained, after evaporation below the original water level, by regularly adding fresh water from a vessel standing near, so that the temperature will not be altered. The aquarium bottom is varied according to the nature and habitat of the animal being studied. Coarse mussel-shell sand is used for Amphioxus and fine slime for marine annelids like Capitella. The burrowing animals are protected from direct sunshine. Where the proper bottom is not provided many burrowing animals lose the habit in confinement. Crustaceans are very sensitive to temperatures higher than 22° Cor lower than 6° C. Some kinds of living plants and animals can be transported from the sea simply in moist water-plants. Those of other species must be placed in individual glass containers, each covered with wet parchment paper and packed in a straw basket and all carried in a
large wooden tub. For especially sensitive animals sometimes a steel flask of compressed oxygen, the "hydrobion," is attached to the transport tank. By means of a reducing valve opened at the beginning of the journey, the flow of oxygen is properly regulated. On account of injury in travelling to the apparatus, or to the animals in striking against the outflow tube, it is found more satisfactory to saturate the sea water with oxygen before the journey and so dispense with the "hydrobion."
The aquarial and circulatory system for fresh water is less complicated than that for sea water since it is not so necessary to use the non-corrosive materials in its construction. The water supply, from a height of 2,000 meters, is free from the excess of lime and phosphorus found in the ground water which comes through the Danube alluvium. The rain water, collected in subterranean cisterns, is also used. The more active animals, especially the carnivorous species which chase their prey, require the larger aquaria. An animal 10 cm. long should be allowed a volume of water of 1 dm3. Carnivorous fishes, crustaceans and aquatic insects must be of about the same size and only a few in each aquarium. To avoid cannibalism the parents must be separated from the eggs, or spawn and the young, except when the parents brood their offspring. Comparatively small vessels are sufficient for indolent forms like tadpoles, salamanders, aquatic insects and most crustaceans. In most cases when breeding, the larger the tank the more certain the result and the more numerous the progeny. Some animals need stagnant slowly flowing water, others a rapid current, some always live in the water, others only during certain times of the year and still others only during certain stages in the life history. Sharp-angled stones are
necessary for certain fishes and amphibia to scrape against in order to remove from their skins such deadly enemies as the fungus Saprolegnia. The annual natural range of temperature must be followed, especially in the breeding of animals. Inhabitants of stagnant pools require a range from 4°-35° C, those of slowly flowing, shallow waters 4°25° C, of the greater depths 4°-18° C, of rushing, rough mountain brooks with shallow places 4°-15*' C. and of caves 12°-17° C. Carnivorous animals need be fed only every other day, and because of the restricted movement in confinement overfeeding leads to fatty degeneration, especially of the reproductive organs. If diseases appear the sick animals must be isolated and the aquaria very carefully cleansed with hot water and the use of disinfectants. Saprolegnia and other ectoparisites are killed by baths of 5 per cent, potassium permanganate, or a light brown solution of ligno-sulphite and ulcerated wounds are touched with a brush, or wad, soaked with concentrated ligno-sulphite.
In the first museums of natural history abnormalities were collected, but later such specimens were discredited as of no value in the system of biological classification and seldom of interest in phylogeny. However, in recent years developmental mechanics has fixed our attention upon the causes of development and by means of the experimental methods many kinds of malformations have been created at will. We now seek the explanation of abnormalities occurring in nature, produced
by "nature experiments," and these monsters and variations again become of value as museum specimens. The results of experimentation carried on in the institution are preserved and exhibited in the museum (Fig. 17), in the form of preparations, photographs and wall charts, and in addition preparations from other experimenters and malformations from nature are being collected. Regarded as of primary importance are the results of experiments concerned with development, regeneration, adaptation, variation in instincts, heredity and species transformation in animals and plants. Of secondary importance are the abnormalities of form and color like supernumerary structures, albino or nigrescent individuals, which have not been produced experimentally, and whose cause is unknown, or at most can only be shown indirectly through analogical deductions. The cases of the museum are located in the entrance hall of the main building and in the adjoining front corridor. Most of the specimens are preserved in fluid, for only a few of the birds and mammals are stuffed and but a minority of the echinoderms and crustaceans are dried. The insects, hermetically sealed in shallow, glass covered cases, represent the influence of temperature upon lepidoptera, of protective resemblance and mimicry, of the series of moultings, of normal growth and growth as influenced by external factors and processes of regeneration, from the egg to the imago. In all cases it is important to have the normal control form exhibited alongside of the experimentally produced variation.
Dr. Przibram publishes a complete list of the animals cultivated in the Vienna institution with important data for each species, concerning the kind of vivarium, or aquarium used, its dimensions and the number of individuals which may there live together, the food, natural habitat and other details, as well as the name of the investigator and publication dealing with each form. The bibliography of papers published by the workers in the institution and Dr. Przibram's summary of these investigations and others being prosecuted furnish an outline of the remarkable scientific productivity resulting from only eight years of research. Such institutions as this of Vienna will do much to solve the great problems of biology. The practise of medical asepsis has permitted operations upon all classes of organisms giving new and valuable data in the field of regeneration. Color has been experimentally investigated as to its nature, whether due to the pigment formation or to the activity of chromatophores, and its relation to light, food, moisture and other external factors as well as its correlation with the animal's vision. By means of the chemical methods of precipitation, agglutination and coagulation, species and hybrids have been tested and the degree of relationship between members of larger groups has been indicated. By the combination of methods of breeding, and subjecting organisms to the influence of changed factors of existence, the laws of heredity will be more clearly established, and the inheritance of functional adaptations acquired under definitely controlled conditions may be demonstrated. The nature of the organ-forming substances in the germ cells and their embryogenesis is being studied. Through physico-chemical methods the biocolloids have become better known and finally the great mystery, the synthesis of living matter itself, may be revealed.
- For his courtesy in lending me the photographs here reproduced and for his paper entitled "Die biologische Versuchsanstalt in Wien," Zeitschrift f. biol. Technik u. Methodik, 1910, I am especially indebted to Dr. Hans Przibram.
- Zeitschrift f. biol. Technik u. Methodik, 1910.