

ZOOLOGY 



ON SERIES IN THE ANIMAL KINGDOM. BY DAVID F. WEINLAND. 



THE existence of certain Zoological groups, namely, those of Classes, 

 Orders, Families, and Genera, was first noticed by the father of Zoology, 

 Aristotle. Two thousand years afterwards, these groups were again brought 

 to light and named by Linnaeus. They have since been improved by Olivier 

 and Baer, and the idea of type has been added. But it was not till lately 

 that the signification, at least of three of them, viz. of Classes, Orders, and 

 Families, was recognized and circumscribed by Agassiz. These ideas will 

 henceforth stand and be acknowledged as founded in nature. 



But the question arises, whether there do not exist still other relations and 

 real affinities of animals to each other, which are not included in these 

 groupings, but which have an equal right to be introduced into our zoologi- 

 cal system. 



We think that this is in fact the case; and we shall endeavor to show 

 in the following sketch that there exist throughout the whole animal king- 

 dom affinities of the animals to each other, which we can comprehend 

 under the name of " Series." About twenty years since, a German natural- 

 ist, Kaup, spoke of series in the animal kingdom, but, his ideas proving 

 somewhat arbitrary, the subject received less attention than it deserved. 

 Nevertheless, its truth, if rightly understood, has been since recognized by 

 some distinguished naturalists. Oken, for instance, spoke of a scale among 

 Articulata, in which he placed the worms lowest, next the Crustacea, and 

 last the insects; and Agassiz has illustrated this gradation fully in the 

 development of the butterfly, and has added still another among insects 

 proper; starting from the principle that the chewing rank below the sucking 

 insects. 



Another order of position has been recognized by Milne Edwards and by 

 Dana among Polypi; another by Leopold von Buch among Cephalopods; 

 another by Dana for Crustacea. We have tried to trace out these grada- 

 tions also among the higher animals, and the success we have met with, 

 wherever we have had accurate information, has convinced us that such 

 gradations, which might very properly be termed series, really exist through- 

 out the animal kingdom. 



Thus, among Mammalia, we have recognized until now two natural series 

 running parallel to each other, a carnivorous and a herbivorous series. The 

 carnivorous begins with the whales, runs through the dolphin, seal, and 

 lutra, to the marten, whence it divides into two branches, one Plantigradous, 



30* 



