The American Naturalist. 



:M;m 



changed, but the cells of the inner one proliferate and begin to lay 

 down the shell, which may be distinguished in sections as a very thin 

 lamina. At about this time observations of embryos by reflected 

 light show a small invagination or hole near the center of the newly 

 formed shell, which is thus laid bare. The hole then is of secondary 

 formation and not, as Korschelt supposes, something that has persisted 

 from the original invagination. 



It appears then that the internal formation of the shell, as it has 

 been generally recognized in the so called naked pulmonates is not an 

 exception to a rule but the rule itself, and that the condition obtaining 

 in Umax and others differs from that in the rest of the pulmonates 

 only in so far as a rudimentary condition is retained in the adult ani- 

 mal.— F. C. Kenyon, Ph. D., Clark University, Worcester, Mass. 



PSYCHOLOGY. 



Physical and Social Heredity.— The great courtesy of the 

 Editor of this journal in reprinting one of my paper from Science pre- 

 liminary to replying to it encourages me to ask him for a page or two 

 of comment on his reply. This is the more needful since the second of 

 my papers which he criticises may not have been seen by the readers 

 of the Naturalist, and the third has only just appeared in Science, 

 (March 20 and April 10, 1896). 



The main question at issue is the relation of consciousness or intellig- 

 ence to heredity ; the other matter, that of the relation of consciousness 

 to the brain, being so purely speculative that I shall merely touch upon 

 it at the end of this note. 



Prof. Cope 1 says : « there is no way short of supernatural revelation 

 by which mental education can be accomplished other than by contact 

 with the environment through sense-impressions, and by t 

 of the results to subsequent generations. The injection of c 

 into the process does not alter the case, but adds a factor which i 

 sitates the progressive character of evolution." Both of these & 

 I fully accept, except that the word " transmission " seem to imply the 

 Lamarkian factor, which I think the presence of consciousness renders 

 unnecessary. Using the more neutral word " conservation " instead of 

 " transmission," I may refer to three points on which Prof. Cope criti- 

 cises my views : first, conservation of intelligent acquisitions from genera- 



1 Amer. Nat., April, 1896, p. 343. 



