Page:Popular Science Monthly Volume 27.djvu/685

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RECENT PROGRESS IN BIOLOGY.
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essential respects. Thus the facts with regard to the growth of birds from the egg are, in regard to large features, the same which have been carefully ascertained with regard to the common fowl. The growth from the egg of ordinary hairy quadrupeds presents the same characters as that of the rabbit, the dog, and man. The history of the changes of the eggs of fish on their way from simple homogeneity to the rich complexity of adult life is practically the same for all fish truly so called; and so we may say of insects—that one insect furnishes the history which is true of all. This, be it remembered, relates only to large and general features. But naturalists are acquainted with a number of strangely abnormal animals which will not enter into large groups and even defy classification, being neither "flesh, fowl, nor good red herring." These recalcitrant animals are not objectionable to the zoölogist; on the contrary, they are his favorites. It is these which he is most eager to study, and it is from them that he expects to obtain information which will clear up doubtful points in the scheme of relationships or pedigree which he has provisionally constructed on the basis of his acquaintance with less isolated forms. These exceptional forms of animal life are found in various parts of the world, and are often difficult of access. Nevertheless, if the naturalist is to study the growth from the egg of these animals, he must follow them to their native homes. Botanists have a great advantage over zoologists in the fact that most plants are readily transported from one locality to another, and can be cultivated in artificial climates produced in glass houses. We have at present no such skill in the treatment of animals, and accordingly the energetic Cambridge naturalists have risen to the necessities of the case. Within the last three years special journeys have been undertaken from Cambridge by members of its biological school to the uttermost parts of the earth, with the sole purpose of studying the growth from the egg of strange and interesting animals, only to be obtained in the remote regions thus visited. Mr. Caldwell, Fellow of Caius College, has gone to Australia, and is still there, for the purpose of studying the history of the growth from the egg of the duck-billed Platypus or duck-mole (Ornithorhynchus) and the spiny ant-eater (Echidna), as well as of the extraordinary lung-bearing, and therefore air-breathing, fish of Queensland known as the Barra-munda (Ceratodus Forsteri). Mr. Adam Sedgwick, Fellow of Trinity College, went in 1883 to the Cape of Good Hope expressly for the purpose of collecting live specimens and, if possible, eggs and young, of a creature very much like a caterpillar in appearance, and known as Peripatus. He obtained the most complete success, brought home to England three hundred living specimens of the extraordinary Peripatus, and has obtained from them since they have been in England young in all stages of development, which will enable him very soon to give a most valuable account of the growth from the egg of this strange form. A third member of the