458 STATUS OF ARISTOTLE IN SYSTEMATIC ZOOLOGY. 
are, if not of circumpolar, at least of subarctic or boreal origin. 
From these facts we are led to accept the conclusions of Les- 
quereux and Gray that co-specific or congeneric forms occurring 
in California and Europe and Asia, are the remnants of a south- 
ward migration from polar tertiary lands during tertiary and even 
perhaps cretaceous times ; and in proportion to the high antiquity 
of the migrations there have been changes and extinctions causing 
the present anomalies in the distribution of organized beings 
which are now so difficult to account for on any other hypothesis. 
For this reason it is not improbable that those species of insects 
which are more or less cosmopolite (and independently so of human 
agency) are the most ancient, just as some forms taxonomically 
the most remote are remnants of earlier geological periods. For 
example, the curious anomalies in the geographical distribution of 
Limulus, the genus only occurring on the eastern coasts of Asia 
and North America, accord with its isolation from other crustacea. 
Geological extinction has gone hand in hand with geographical 
isolation. It was a common form in Europe in the jurassic period, 
and in the next lower (permian) period but one (the triassic inter- 
vening) we find other Merostomata and a few Trilobites. 
We make these speculations hoping that much light will be 
thrown upon the subject by studies on the rich tertiary insect 
beds of the west, and of the fossil insects in the arctic tertiary 
and cretaceous formations. Until then we must regard all foun- 
dations for these hypotheses as laid by the fossil botanist. 
. 
ON'THE STATUS OF ARISTOTLE IN SYSTEMATIC 
alae! ZOOLOG 
BY THEODORE GILL, M.D., PH. D. 
ğ PEN ; 
Sucu extravagant claims have been urged in favor of the recogni! 
tion of Aristotle as an exponent of. classificatory science, and as 4 
model meet to be followed by the naturalists of the rising genera- 
tion, that it may be timely to inquire into the merits of such claims; 
must, of course, in justice to the ancient author, exclude from con- 
S 
and whether they are really justified by his works. In doing 50 Wè 
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