ORIGIN OP CAVE LIFE. 
27 
Scliiodte spends its life in crawling ten to twenty feet above the 
floor over the colninns formed by the stalactites, to which unique 
mode of life it is thronghont perfectly adapted, is remarkably 
different from other Silphids. Its legs are veiy long and inserted 
far apart (the prothorax being remarkably long), with surprisingly 
long claws, -while the antennse, again, are of great length and 
densely clothed with hairs, making them most delicate sense or- 
gans.* So also are the limbs of the false scorpion, and the spi- 
der and pill bug (Titanethes) of remarkable length. 
Blit the modiflcations in the body of the Spirostrephon are such 
that many might deem its aberrant characters as of generic impor- 
tance. It loses its eyes, which its nearest allies in other, but 
smaller, caves possess, and instead gains in the delicate hairs on 
its back, w^hich evidently form tactile organs of great delicacy ; 
the feet are remarkably long, as also the antennm. These are not 
new formations but simply modifications, apparently by use or dis- 
use, of organs present in the other species. The aberrant myrio- 
pod and Stagobius are paralleled by the blind fish, an animal so 
difficult to classify, and so evidently adapted for its abode in end- 
less darkness. And as an additional proof of the view here taken 
that these cave animals are modified from more or less allied spe- 
cies existing outside^ of the caves, we have the case of the craw 
fish, whose eyes (like those of the mole), are larger in the young 
than adult, indicating its descent from a species endowed with the 
faculty of sight, while in the adult the appendages are modified as 
tactile organs so as to make up for its loss of eyesight, in order 
that it may still take its prey. 
We thus see that these cave animals are modified in various 
ways, some being blind, others very hairy, others with long ap- 
pendages. All are not modified in the same way in homologous 
organs ; another argument in proof of their descent from ancestors 
"*=Schiodte remarks that “it is difficult to understand the mode of life of Stagobius 
troglodytes; or how this slow and defenceless animal can escape being devoured by the 
rapid, piratical Arachnidans, or find adequate support on columns, for inhabiting 
which it is so manifestly constructed. We are led in this respect to consider the anten- 
nte. Whatever significance we attach to those enigmatical organs, we must admit that 
they are organs of sense, in which view an animal having them so much developed as 
Stagobius, must possess a great advantage over its enemies, if these be only Arachni- 
dans. Its cautious and slow progress, and its timid reconnoitring demeanor, fully 
indicate that it is conscious of life being in perpetual danger, and that it endeavors to 
the utmost to avoid that danger. Darkness, which always favors the pursued more 
than the pursuer, comes to its aid, especially on the uneven excavated surface of the 
columns.” 
