Popular Science Monthly/Volume 44/February 1894/A Marine Biological Laboratory
|NOTES FROM A MARINE BIOLOGICAL LABORATORY.|
FOR the past fifteen years it has been customary for the members of the Biological Department of the Johns Hopkins University to devote the summer vacations to pursuing their studies on the seashore. "The Johns Hopkins Marine Laboratory," as the organization is called, is under the direction of Prof. W. K. Brooks, and has been confined to no permanent location, but has been moved from place to place as the wishes of those interested demanded. Many seasons were spent in studying animal forms found in waters of the Chesapeake Bay. For a few years the laboratory was stationed at Beaufort, N. C. Then Green Turtle and Biminy Islands of the Bahamas were chosen as stations for biological research. Finally, the organization went so far south as the island of Jamaica. The site of the present marine laboratory is Port Henderson, Jamaica, where it was located two years ago. To secure best results in research upon embryonic forms, our party set out early for the sea. With full equipment for the laboratory we boarded the steamer Ryvingen and sailed down the Chesapeake Bay en route for the West Indies. The voyage was uneventful for the most part. After the lighthouses and white sandy hills of the Eastern Shore had disappeared beneath the horizon, we continued our course steadily to the southeast, with little to entertain us but occasional schools of flying fish and the flock of "Mother Carey's chickens" which followed our boat all the way. Large jellyfish and ctenophores floated by occasionally. On the fourth day out we passed Watling's Island, or San Salvador, and other smaller islands of the Bahamas. Next day we rounded the eastern coast of Cuba, and by using the captain's field glass could easily determine the characteristic features of the island. Its mountains appear quite high and rugged in the interior, and they slope rapidly by foothills and broad terraces down to the sea. The shores of Cuba afforded us our first glimpse of cocoanut palms, banana and sugar-cane plantations. It was a beautifully clear and starry night when we sailed into Windward Passage. The gray mountains of Cuba outlined against the northern horizon were slowly fading from view, when the crescent moon arose out of the waves in the east. The north star hung low, and in the south the Southern Cross appeared to us for the first time. With such new and charming surroundings we spent the evening very delightfully on deck. Not the least interesting was the phosphorescence in the waves and spray. Each crested wave, as it receded from the bow, seemed alive with hosts of glowing fireflies. It was a grand sight to watch the turbulent, sparkling stream that followed in the ship's wake. Disturbed by the motion of propeller and rudder, millions of minute phosphorescent organisms were thrown to the surface like brilliant, sparkling gems. Now and then large ctenophores emerged from the depths, displaying rich halos of light for a moment, then disappeared in the surf. In no other place did we notice such rich displays of phosphorescence.
After a six-days' voyage we landed safely at Port Henderson, on the north side of Jamaica. Here we took carriages for a drive of sixty miles across the island to Kingston, its capital. The road
we traveled was a well-built public thoroughfare, fully equaling the American "gravel road." It followed the coast line pretty closely for twenty-eight miles to Annotto Bay, then extended into the interior by way of the Wag Water River. Reaching the "divide" of the Blue Mountains, the road rapidly descended by a circuitous route into the broad valleys of the south side of the island. This drive across Jamaica affords the tourist a fair idea of its life and scenery. The majestic cocoanut palm, the luxuriant banana plant, and the feathery bamboo grace the landscape in every direction. The primitive bamboo cabins, with their dusky occupants, the barefooted market women, "John Crow" the buzzard, and "Old Joe" the pelican, soon become familiar objects to the tourist in the West Indies. On reaching Kingston we found our way through its narrow streets to Market Wharf, where we took passage on the steam launch Firefly for Port Henderson, our final destination. This is a little village of a dozen or more buildings lying across the harbor to the southwest about four miles from Kingston. It is a seaside resort for Jamaicans of leisure, and a more attractive and suitable spot about the harbor could not have been chosen. In the rear of the village Salt Pond Hill rises abruptly to a height of one thousand feet or more, and upon its highest point are the ruins of an old stone fort known as "Rodney's Lookout." From this position a glorious view of the surrounding country is obtained. Here, in the early days of pirates and buccaneers. Admiral Rodney had his stronghold, whence he could look out upon the harbor and sea and detect the approach of enemies.
From the veranda of our laboratory we had a grand view of Kingston Harbor, in which the entire fleet of the English navy might anchor with safety. Following the low, sandy beach to the left we see the fishermen's hamlets and old Port Augusta. Across the harbor the city of Kingston appears in dim outline; and off to the right, upon the end of the "pallisadoes" protecting the harbor, lies old Port Royal, which was nearly destroyed by the earthquake of 1603. To the southeast the harbor opened out into the deep waters of the Caribbean Sea. The beautiful landscape stretching out thus before us was completed by the Blue Mountains, which formed a dark gray background. The highest point of the range is Blue Mountain Peak (7,560 feet). It appears in bold relief above the range, twelve miles east of Kingston, Two years ago some of our party made the ascent of the mountain. They encamped on the peak overnight, and enjoyed the rare luxury of soft beds of tree-fern leaves improvised for the occasion. The location of our laboratory offered many facilities for biological research. Numerous coral reefs, mangrove swamps, and salt ponds were all within an hour's sail from our port. Good opportunity for study is also found on land. The hills in the rear and the broad valley of the Rio Cobre, not far away, are stocked with land crabs, lizards, termites, scorpions, and the like. Bird life is not so abundant as we had anticipated, but to a botanist the flora of Jamaica offers a most attractive field for study.
By those who are acquainted with the coast of Jamaica, Port Henderson is thought to be the most suitable location on the island for a permanent marine laboratory. It offers many advantages for study of life in tropical waters; its collecting grounds and its facilities for "towing" and "dredging" are next in value to those of the Gulf Stream. The location is in the immediate vicinity of Kingston, whence the temporary wants of the party may be readily supplied. It is also in direct communication with New York and Liverpool by steamer and cable. With a view, then, of locating a permanent laboratory for promoting the study of marine biology, a plan is at present being considered by
prominent biologists at home and abroad for establishing an "International Marine Biological Station" at the place above named. It is sincerely hoped that the preliminary steps taken in this direction may lead to the establishment of the much-needed institution on American shores.
The building which we called our "Marine Laboratory" was a large, one-story stone structure, known as the "Sister Houses." It was light, airy, and comfortable, affording ample room for our party of seven. Each member of the company occupied a separate table, and upon this his microscope was placed, together with a varied collection of specimens, "preserving" fluids, dishes, scalpels, etc., the whole forming a veritable "biologist's corner." In other parts of the building were our nets, buckets, jars, gun, and dredge, also books and chemical reagents, arranged as occasion and space suggested.
Our usual programme for the day began with early coffee and toast; then we repaired to our sloop with nets, water glass, dredge, etc., and rowed out to the coral reefs or so-called cays. Landing on one of these, we waded about in water, varying in depth from tiny waves that rippled over the sandy beach to breakers whose white crests dashed over our shoulders, and filled our faces with salty spray. After collecting for two or three hours we would sail for port. One rule adopted for these expeditions shows the ease and freedom existing among the members of our party—i. e., "No one is allowed to capsize the boat more than three times; more than this is considered dangerous on account of sharks." The regulation was closely observed. When the laboratory was reached, the morning's collection was set aside for an hour, while all prepared for breakfast by taking a plunge into a large swimming pool near by. Our meals were served after the English custom prevailing on the island, and were characterized by a large variety of tropical fruits and vegetables. The Ripley pineapples, No. 11 mangoes, and sapodillas were luscious fruits, but quite forgotten when we returned to the States and found American melons and peaches. After breakfast the remainder of the day was generally devoted to the study and preservation of the morning's collection. After a lunch of fruits and limeade we frequently took walks over Salt Pond Hill or up the valley of the Rio Cobre, in search of termites, scorpions, centipeds, and lizards. Late in the evening was the best time for "towing," although we often went out early in the morning. To do surface collecting we would row out upon the quiet bay about a mile from shore, then throw out two nets made of fine silk bolting cloth. These were tied by long cords to the stern of the boat, so as to drag near the surface of the water. The nets were carefully emptied into buckets of fresh sea water every few minutes. The "tow," or material thus captured, was taken directly to the laboratory and examined. By dipping out small portions in glass dishes and holding them up to the light we could detect a great number of minute pelagic animals swimming about in great commotion. These "surface collections" are intensely interesting, for in them the biologist finds multitudes of embryonic forms in various stages of their development. The larvæ of starfish, sea urchins, shrimps, conchs, and other forms, appear in their normal living state under his lens. Besides larvæ, numerous adult forms, as Sagitta, Appendicularia, platoid worms, Medusæ, and green Algæ, are collected. A careful survey of the hosts of forms thus captured, and a fair understanding of their true significance, prepare one for the often-repeated statement that "the ocean is the original home of all life." We are impressed with the fact that it is from this source that we must seek further information that shall throw light upon many biological problems at present unsolved. A few days of general collecting in the sea suffices to reveal the great abundance of life in the ocean as compared with its scarcity on land.
The various expeditions taken by our party in the tropics would have been interesting and enjoyable to almost any one. To the casual observer they may have presented the appearance of pleasure excursions, rather than trips for earnest work and study.
On one occasion we sailed to Salt Pond, a kind of lagoon bordering the sea, where numbers of crocodile and turtle were frequently found. We had been rowing about for some time in the pond with no success except that of catching mullet with a throw-net, and taking note of the numerous cranes, pelicans, and bitterns flying about, when we came upon a "crocodile slide." This is a smooth, broad trail leading up the bank, which the beast follows when it wishes to prepare a nest in the sand for its eggs, or take a ramble beneath the underbrush.
No sooner had we neared the slide than here came a frightened crocodile about seven feet in length, dragging himself down the slippery bank into the water. As it swam out in front of our boat, its black nose protruded above the surface, offering a fine shot, but fortunately for the crocodile our gun was left at home.
Before leaving the pond we secured a fine collection of large, beautiful jellyfish (Cassiopea), and luckily for us the boatman discovered a dozen or more little crocodiles among the mangrove roots; we all repaired to the scene, and amid much excitement succeeded finally in capturing one.
One of the most productive collecting fields for our studies was that in the mangrove ponds off the "pallisadoes," near Port Royal. The mangroves in this region have extended into the shoal water, thus forming a number of quiet ponds and canals. We found life very abundant here. Upon the mangrove roots great clusters of Clavelina, simple ascidians, and colonies of hydroids hung near the surface of the water. Battery actinians and Botryllus grew in the warm waters, attached to blades of eel grass. Echinoderms were very abundant. Sea urchins (Strongylocentrotus) were thickly strewn over the bottoms of the ponds. Of starfish we collected three forms (Echinaster, Asteropectin, and Astorina). For holothurians no other place along the coast was better. They were profusely scattered about over the muddy bottoms of the ponds. Some were dark brown, others large and spotted, growing to a length of eight and ten inches. Our experience in collecting and preserving these large holothurians was always exasperating, for,
try any experiment we might, they would always end with negative results. About the time we considered them fully narcotized they began contracting the muscles of the body walls, then suddenly eviscerated themselves. One very interesting form (Synapta vivipara) was found in great numbers growing among the filaments of a certain alga in the ponds. Sponges, gasteropods, and annelids were also numerous about the mangroves.
Taking the animals alive to the laboratory was an important part of our expeditions. For this purpose we used water buckets and open jars. The various specimens were distributed in different vessels, so as not to be crowded; these were allowed as much fresh sea water as possible, which was changed repeatedly.
Of all our excursions during the season, those of most popular interest were to the cays which were out in the Caribbean Sea, two to ten miles from our laboratory. They may be described as small islets jutting above the waves a few feet. Some were covered with mangrove bushes, others were of bare rock and sand, over which large waves would break. By overturning stones in the shallow water we found many interesting animals. Brittle stars and sea baskets often shared their homes with spiny annalids and coiling synaptas. Darting about among the rocks were little rock crabs, young lobsters, and small shrimps. Beautiful sea anemones and turbellarian worms were numerous upon the rocks. Wading out a few steps into the deeper water we came to rich coral formations; and looking through a water glass we could see as through an open window into these beautiful gardens under the sea. There were massive brain corals (Meandrina) growing in scattered groups, with other interesting species between; clusters of star corals (Astræa) and branching stag-horns (Oculina) covered large areas. In the clear, open spaces were exquisite sea fans and sea feathers (Alcyonaria) waving their graceful forms to and fro with the tide. The scene was made even more charming when schools of beautifully colored coral fish, goldfish, and mullet swam in and out among the corals and into the open sea. A poet has seen these quiet parlors of the fishes and thus described them:
"There with a light and easy motion
The fan-coral sweeps through the clear, deep sea,
And the yellow and scarlet tufts of ocean
Are bending like corn on the upland lea,
And life in rare and beautiful forms
Is sporting amid those bowers of stone;
Where the purple mullet and goldfish rove,
Where the waters murmur tranquilly,
Through the bending twigs of the coral grove."
Any report of the Johns Hopkins Marine Laboratory in Jamaica would be incomplete without mention of the kind hospitality shown us by the citizens. Our party was cordially received wherever it went; and at the laboratory we were honored by calls from chief officials residing in Spanish Town, Kingston, and Port Royal. As a body of American students, we had the pleasure of taking lunch at "The King's House" with Lady Blake, the governor's wife. It was very gratifying to find the prominent citizens of Jamaica enthusiastic in their encouragement of biological research on the island.
As to the results of the summer's work in the tropics, little can be said at present that is final, since much of it is not yet completed. A good quantity of valuable material was preserved for future study. Very full notes and drawings of the animals in their living and normal condition were made. These notes and drawings, together with the alcoholic specimens, are stowed away awaiting further investigation, to be carried on chiefly at the Johns Hopkins University.