158 . GLEANINGS FROM NATURE. 



The pupal cases are dark gray, densely felted, and 

 one-fourth of an inch or more in length. They were 

 found attached to small projections of the wall, close 

 to the floor, or on the under side of stones which rested 

 loosely on the floor. 



The moth seldom flies, but crawls very rapidly or 

 leaps short distances, when disturbed. It was first 

 described in Europe, where it occurs among pelts and 

 furs. Its presence in Wyandotte Cave can only be 

 accounted for by its accidental introduction on the 

 clothing of guides or visitors. As yet it shows no dif- 

 ference in color or structure from open-air types of 

 the same species, but it is not unreasonable to suppose 

 that in years to come there may be perceptible modi- 

 fication in these respects, as has been observed in 

 other cave inhabiting forms. 



The introduction of this European moth into a cave 

 like Wyandotte, and its rapid adaptation to the peculiar 

 environment there found, is an excellent proof of the 

 now commonly accepted theory that all cave animals are 

 but the descendants of seeing forms, which in the past, 

 have thus accidentally found their way into caverns. 



In the same region in which the moth occurred 

 were numerous specimens of a small dark-brown gnat 

 or fly about one-twelfth of an inch in length. It was 

 found to be new to science, and has since been de- 

 scribed as Limosina tenebrarum Aldrich. It occurs 

 beneath stones, in the vicinity of the remains of bats 

 which are killed in numbers by the cats which fre- 

 quent the cave. This insect has the power of leaping 

 several inches when disturbed and seldom uses the 

 wings in endeavoring to escape. 



