750 THE MAMMOTH CAVE AND ITS INHABITANTS. 
moth Cave, a brownish centipede-like myriopod, over an inch in 
length, which moved off in a rapid zigzag motion. Unfortunately, 
he did not capture it. 
Next to the blind fish, the blind crawfish attracts the attention 
of visitors to the cave. This is the Cambarus pellucidus (Fig. 
Fg. 131. 131, from Hagen’s 
monograph of the 
North American 
\ | Astacidæ) first de- 
\ i scribed by Dr. Tell- 
j kampf. He re- 
; marks that “the 
j eyes are rudiment- 
| ary in the adults, 
but are larger in 
the young.” We 
might add that this 
is an evidence that 
the embryo devel- 
ops like those of 
the other species; 
and that the inher- 
itance of the blind 
condition is proba- 
bly due to causes 
first acting on the a- 
dults and transmit- 
ted to their young, 
until the production 
of offspring that be- 
L= come blind becomes 
| a habit. This is 
a partial proof at 
AN 
Gig ka least that the char- 
hd! ALA CII acters separating 
the genera and spe- 
: cies of animals are 
those inherited from adults, modified by their physical surround- 
ings and adaptations to changing conditions of life, inducing cer- 
tain alterations in parts which have been transmitted with more or 
Cambarus pellucidus. 
