216 SUBTERRANEAN ANIMALS AND PLANTS. 



deposited over dead insects lying in the cave. " These . . . were interest- 

 ing as showing how pseudomorphs of organic forms might be developed 

 in caverns." 



Both of these species of myriapods are blind, although seven other 

 closely related species have the power of sight, which leads Professor 

 Kyder to make some cautious remarks, a part of which I am persuaded 

 to quote: 



" In the absence of proof to the contrarj', with the increase in the 

 number of known blind forms which are often congeneric with light- 

 loving species, there is the strongest kind of ground for supposing that 

 they have descended from forms which had eyes, and which wandered 

 into these recesses, where, after many generations had lived and died, a 

 blind form appeared, which resulted from the gradual abortion of the 

 visual organs of its ancestors. In proof of this we have the partially 

 blind Orchesella, which now seems to be verging towards such a condi- 

 tion. In the absence of a greater number of facts we are not justified 

 in inferring more. True, we have a few instances among mollusks, some 

 of which in their larval states have useful eyes, but which afterwards 

 become useless and abort as the shell develops and gets thicker. Some 

 terrestrial myriapods are blind, such as Eurypauropus ; so is Lwnibri- 

 cus, the earth-worm, and some of the dirt -abiding Thysanura, which 

 also live among fallen leaves, such as Campodea ; while in the burrow- 

 ing Symphyla (scolopendrellw) the eyes are reduced to a single pair, with 

 little or no red or dark coloring in the tapetum, differing widely in this 

 respect from the compound-eyed terrestrial myriapods." 



A few bats and fewer rats make the entrance portions of the cave 

 their retreat ; and there seems to be no aquatic life in the pools, which 

 nowhere form a stream communicating with the outer world so as to 

 admit such denizens as the strange blind fishes and crawfish found in 

 the Mammoth Cave. The vegetation is chiefly, perhaps wholly, repre- 

 sented by a long white mould which collects upon the under side of the 

 green planks taken into the cavern for walks and stairways, and hangs like 

 Spanish moss in quaint imitation of the ponderous stalactites overhead. 



Out into the warm, sweet air again, all the world looks fairer for 

 one's temporary occultation. Surely the Troglodytes had a hard lot. 

 Even the Naiads under the water, and the Nereids, though indissoluble 

 from growing trees, were better off! 



Subsequent to my visit to the caverns of Luray, I inspected a cave 

 near Manitou, Colorado, which proved to bear a striking resemblance to 



