418 ON THE. WYANDOTTE CAVE AND ITS FAUNA. 
or less herbivorous. They furnish food for the spiders, eraw-fish, 
Anophthalmus, and the fish. The vegetable food supporting them is 
in the first place fungi, which in various small forms, grow in 
damp places in the cave, and they can always be found attached to 
excrempntitious matter dropped by the bats, rats and other ani- 
mals which extend their range to the outer air. Fungi also grow 
on the dead bodies of the animals which die in the caves, and are 
found abundantly on fragments of wood and boards brought in by 
human agency. The rats also have brought into fissures and cay- 
ities communicating with the cave, seeds, nuts and other vegetable 
matters, from time immemorial, which have furnished food for 
insects. Thus rats and bats have, no doubt, had much to do with 
the continuance of land life in the cave, and the mammals of the 
post-pliocene or earlier period, which first wandered and dwelt in 
its shades were introducers of a permanent land life. 
As to the small crustaceans, little food is necessary to support 
their small economy, but even that little might be thought to be 
wanting, as we observe the clearness and limpidity of the water 
in which they dwell. Nevertheless .the fact that some cave waters 
communicate with outside streams is a sufficient indication of the 
presence of vegetable life and vegetable débris in variable quar 
tities at different times. Minute fresh water alge no doubt occu! 
there, the spores being brought in by external communication, 
while remains of larger forms, as còonfervæ; etc., would occur 
plentifully after floods. In the Wyandotte Cave no such coune? 
tion is known to exist. Access by water is against the current of 
small streams which discharge from it. On this basis rests an ani- 
mal life which is limited in extent and must be subject to many 
vicissitudes. Yet a fuller examination will probably add to the 
number of species and of these, no doubt, a greater or less pe 
ber of parasites on those already known. ‘The discovery of a 
little Lernæan shows that this strange form of life has T 
all the vicissitudes to which its host has been subjected- “of 
it has outlived all the physiological struggles which . chang 
light and temperature must have produced, and that it still prey” 
on the food of its host as its ancestors did, there is n0. ae 
The blindness of the fish has favored it in the “ struggle for®* 
ence,” and enabled it to maintain a position nearer the: eo ae 
sariat, with less danger to itself than did its forefathers. 
