io8 THE POPULAR SCIENCE MONTHLY. 



Professor S. A. Forbes,* in a study of the " Blind Cave Fish and 

 their Allies," is led to review the conclusions reached by Professor F. 

 "VV. Putnam in his interesting papers on the subject. Professor Put- 

 nam brought forth a number of arguments which seemed to him to 

 militate against the views urged by evolutionists that their peculiar 

 characters were adaptive and the result of their cave-life. He was led 

 to the conclusion that the absence of light had not brought about the 

 atrojjhy of the eyes, the development of special sense-organs, and the 

 bleaching of the skin. In referring to another cave-fish, Chologaster, 

 with eyes fully developed, it was urged that the argument in regard 

 to eyeless fishes could have no weight. In response to this it was an- 

 swered that possibly Chologaster had not been subjected to subterra- 

 nean influences long enough to be affected, and this objection was an- 

 ticipated by urging that we have no right to assume that Chologaster 

 is a more recent inhabitant of the caves, until proved. 



The discovery of another species of Chologaster, taken from a 

 spring at the base of a limestone cliff in Illinois, has given Professor 

 Forbes an oj^portunity to make careful comparisons with the cave 

 Chologaster. He says in regard to it, " The most important and 

 interesting peculiarity of this species indicates a more advanced stage 

 of adaptation to a subtei-ranean life than that of its congeners." Re- 

 ferring to Professor Putnam's arguments. Professor Forbes says that 

 "the discovery of a species of Chologaster, which frequents external 

 waters, of an immediate subterranean origin, supplies all needed proof 

 that the genus either has a shorter subterranean history than Ambly- 

 opsis, or, at any rate, has remained less closely confined to subterranean 

 situations ; and that in cither case the occurrence of e3"es, partial ab- 

 sence of sensory papilla3 and persistence in color, are thus accounted 

 for consistently with the doctrine of 'descent with modification.'" 

 In this connection it may be of interest to read the curious fact re- 

 corded by Mr. S. II. Trowbridge,f of the discovery in the Missouri 

 River of a shovel-nosed sturgeon which had the skin growing over the 

 eyes, completely inclosing them. Dr. S. II. Scudder,J in a memoir 

 read before the Kational Academy, brings forward evidence to show 

 that ordinal features among insects were not differentiated in Pala?ozoic 

 times, but that " all Palaeozoic insects belonged to a single order which, 

 enlarging its scope as outlined by Goldenberg, we may call Pal»o-dic- 

 tyoptera ; in other words, the palocozoic insect was a generalized hexa- 

 pod, or more particularly a generalized Heteromctabolon." In a 

 memoir on the earliest winged insects of America, embracing a re- 

 examination of "The Devonian Insects of New Brunswick," published 

 by the author. Dr. Scudder replies to some sharp criticisms and ob- 

 jections made by Dr. Hagen, and pertinently says, that "there is 

 no evidence — but the contrary — that Dr. Hagen in his investigations 



* "American Naturalist," vol. xvi, p. 1. f "Science," vol. iii, p. 587. 



X "American Naturalist," vol. xix, p. 877. 



