ZOOLOGY. 



By Dr. A. S. PACKARD, Jr., 



Professor op Zoology and Geology, Brown University, Providence, R. I. 



GENERAL ZOOLOGY. 



From a review of the year's progress in general zoology, 

 it appears that more and more attention is being paid to the 

 embryology and histological anatomy of animals, especially 

 in Germany and England. The most important discoveries 

 in embryology are the elaboration, by Salensky in Germany, 

 of the embryology of the sturgeon, his researches confirming 

 Geo-enbaur's view of the vertebrate theory of the skull. In 

 this country, Agassiz has cleared up the early history, after 

 hatching, of the gar-pike. In England, Parker has worked 

 out the development of the snake. Important results in zoo- 

 geography, especially of birds, have been published by Coues 

 and others. 



Mr. Francis Darwin has lately been discussing the analo- 

 gies of plant and animal life. Some of the points of resem- 

 blance are purely analogical ; nevertheless he attempts to 

 show that "a true relationship exists between the physiolo- 

 gies of the two kingdoms. Until a man besrins to work at 

 plants he is apt to grant to them the word 'alive' in rather 

 a meagre sense. But the more he works, the more vivid 

 does the sense of their reality become. The plant physiolo- 

 gist has much to learn from the worker who confines himself 

 to animals. Possibly, however, the process may be partly re- 

 versed it may be that from the study of plant physiology we 

 can learn something about the machinery of our own lives." 



In a paper on the individuality of the animal body, Haeck- 

 el says that the actual organism (bion) is an unjointed bilat- 

 eral person, without segments, with a few antimeres. In the 

 Arthropoda (crustacea and insects) the mature physiological 

 individual is jointed, two-sided or bilateral, with a few anti- 

 meres (limbs or appendages) and numerous segments. In 

 these last there is an ideal psvchic bond of a community of 



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