MUSEUM OF COMPARATIVE ZOOLOGY. 227 



In one letter Miss Hoppin says : — 



" I took a boy with me and went to Wilson's Cave. The catch was not 

 large, but I was much encouraged by what I learned while there. The cave is 

 about fifty feet long, nearly as wide, oven-shaped, and high enough to stand 

 erect except around the sides. The farmer had enlarged the entrance to use 

 the place as a creamery. A small very clear stream flowed along the left side, 

 having a width of two feet and a depth of three, with a temperature of -f-54° F. 

 About ten feet from the entrance the light struck the stream in such a manner 

 that we could see everything in the water without a lantern. The first things 

 that caught the eye were a lot of white crayfish, a dozen in all, like those I 

 took from the wells. It seemed as if I might take every one of them. But 

 though blind, they have one or more of the other senses very keenly developed. 

 I am very sure they, as well as the white fishes, have the tactile sense developed 

 in an unusual degree. At the least touch upon the water they dart away. As 

 the net cautiously follows, they escape adroitly, making no blunders as to the 

 direction of the approaching enemy, and hide in crevices of the jutting rocks or 

 in the muddy bottom of the stream. The mud was easily stirred so that noth- 

 ing could be seen. These creatures, fish and crayfish, are only to be secured 

 by patient waiting and skilful management. The people at the cave say the 

 fish never bite, and cannot be taken with hook and line. The crayfish were 

 all found near the entrance, where there is considerable light. Following the 

 stream back to a dark recess, reached by crawling on the slippery rocks, the 

 light of the lantern revealed a school of little white fishes, such as I secured 

 from the wells. All were very small. I saw half a dozen or more, but 

 secured only one. I concluded the crayfish liked the light. Perhaps they 

 remain near the entrance because they find there a supply of food. We found 

 a few snails floating about, but saw none in the dark pool where the fish were. 

 Miss Wilson, who was with me, thinks the crayfish devour the others. She 

 has never seen them together, and says the latter keep away from the former, 

 though she had not noticed the crayfish catching or eating them. There was 

 nothing to prevent the crayfish ascending the stream to where the others 

 were. 



" An insect, a ' water spider,' common outside, is found inside near the light. 

 1 did not find it back where the little fishes stayed. By crawling back under 

 the rocks one could see where the stream issues from the crevice. The passage 

 is too low and too small to be followed, as the water occupies almost the whole of 

 the openiug. Beyond it, I think, one would find the home of the fish. The low 

 opening is arched over by solid limestone, and could hardly be enlarged arti- 

 ficially, as the main entrance has been. Several feet to the right of the stream, 

 having no visible connection with it, is ' the lake,' about fifteen feet in 

 diameter. It is now a muddy bed. In no place could I see an inch of clear 

 water. Just at the centre it has most water. When the water is high, the 

 lake is full of fishes. What becomes of them when the water is low ? I am 

 ashamed that I did not look into that mud a little more carefullv. There 



