92 FAUNA OF MAYFIELD'S CAVE. 



Concerning the food of cave animals in general comparatively little 

 has been published, although the foodof ^m6^7yops?*shas been well under- 

 stood for some time. Packard (1876, 285) mentions the abundance of 

 Pseudotremia cavernarum about bits of candle-drip in caves and in the 

 same paper and later in his monograph (1888, 24, 25) mentions the 

 probable food of certain cave animals. Cope (1871, 13) remarks upon 

 the scantiness of food of cave animals and offers a suggestion as to the 

 source of the supply through vegetable matter swept into caves by 

 water. Chilton (1894, 264) confesses inability to add to the knowledge 

 of the food of subterranean crustaceans. Carpenter (1895, 33) notes 

 that Lipura gets its food by engulfing quantities of the fine earth, from 

 which it obtains vegetable mold, and mentions the fact that "collectors 

 in the Carniolan caves secure insects by leaving pieces of wood as 

 traps." The food problem is a difficult one, and I have gotten far less 

 light on the subject than I had hoped. 



Throughout the paper mention has been made of the food and feeding 

 habits of the different species so far as observed. It may be well to 

 recapitulate somewhat here. Sciara, Aphiochseta, Lhnosina, and the 

 staphylinidous beetles are found in greater abundance at decaying animal 

 matter; Ceutkophilus, the cave myriapod, and the cave thysanuran are 

 about equally abundant at decaying organic matter, whether animal or 

 vegetable. As stated before, any bit of organic matter of whatever 

 sort serves to attract cave Arthropods in considerable numbers. Light 

 disturbs these creatures, so that it is well-nigh impossible directly to 

 observe their feeding in the cave, but all have been so nearly caught in 

 the act of feeding that the cases are practically proven. The spiders are 

 probably predaceous in the main, but Phanetta siibterranea and Erigone 

 infernalis may feed upon decaying organic matter also. The former 

 was observed to catch a thysanuran, and at another time one was found 

 which seemed to be feeding upon cheese. The crustaceans are preda- 

 ceous as well as being scavengers. The Anopthalmns is predaceous. 



In fig. 13 an attempt is made to represent in a graphic way the 

 dependence of cave animals upon organic matter carried into the cave 

 and to show the food relation of cave species to one another. 



The fact that all of these animals are absolutely dependent directly 

 or indirectly upon decaying organic matter brought into the cave from 

 outside by the merest chance and accident must not be lost sight of. 

 It will readily be seen, too, that there is a close relationship as regards 

 food between the different cave forms, an interdependence so complete 

 that were certain groups removed others must perish because of their 

 dependence upon them. 



The habits of cave species so far as learned are exactly similar to 

 the habits of their near relatives outside of caves. This statement 



