26 
ORIGIN OF CAVE LIFE. 
Assuming on the principles of evolution that the cave animals 
were derived from other species changed by migration from the 
outer world to the new and strange regions of total darkness, it 
seems evident that geologically speaking the species were suddenly 
formed, though the changes may not have been wrought until after 
several thousand generations. According to the doctrine of natu- 
ral selection, by which species pass from one into another by 
a great number of minute variations, this time was not sufficient for 
the production of even a species, to say nothing of a genus. But 
the comparatively sudden creation of these cave animals affords, it 
seems to us, a very strong argument for the theory of Cope and 
Hyatt of creation by acceleration and retardation, which has been 
fully set forth in this journal. The strongly marked characters 
which separate these animals from their allies in the sunlight, are 
just those fitting them for their cave life and tliose which we would 
imagine would be the first to be acquired by them on being re- 
moved from their normal habitat. 
On introducing the wingless locust, CeuthopkUus macidatus^ 
into a cave, where it must live not under stones, but by clinging to 
the walls, its legs would tend to grow longer, its antennae and 
palpi would elongate and become more delicate organs of hearing 
as well as touch,* and the body would bleach partially out, as we 
find to be the case in H. suhterranea and (7. stygia. The Carabid 
beetle, Anopthalmus, extending farther into the cave, would lose 
its wings (all cave insects except the Dipterahave no wings, elytra 
excepted) and eyes, but as nearly all the family are retiring in 
their habits, the species hiding under stones, its form would not 
undergo farther striking modification. So with the blind Campo- 
dea, which does not differ from its blind congeners, which live 
more or less in the twilight, except in its antennm becoming 
longer. The blind Adelops, but with rudiments of eyes, does not 
greatly depart in habits from Catops, while on the other hand the 
remarkable Stagobius of the Illyrian caves, which according to 
* After writing this article, and without knowledge of his views, we turned to Darwin’s 
Origin of Species to learn what he had to say on the origin of cave animals. He attri 
butes their loss of sight to disuse, and remarks : — “By the time an animal has reached, 
after numberless generations, the deepest recesses, disuse will on this view have more 
or less perfectly obliterated its eyes, and natural selection Avill often have effected 
other changes, such as an increase in the length of the antennae or palpi, as a compen- 
sation for blindness.” 5th Amer. Edit., p. 143. We are glad to find our views as to the 
increase in the length of the antennae and palpi compensating for the loss of eyesight, 
confirmed by Mr. Darwin. 
