1895.] Psychology. 873 
The sperm-plug that was present in the annulus also disappeared a 
day later than the secretion, As this crayfish was alone, it seems certain | 
that she removed the sperm-plug. It remained for weeks in cases where. 
eggs were not laid. 
The eggs, however, seem not to have been fertilized: they gradually 
fell off and burst from osmotic changes. . A, ANDREWS. 
PSYCHOLOGY.’ 
Professor Baldwin on ‘‘ Mental Development.’’—It gives 
me pleasure to insert the following note which Professor Baldwin has 
recently sent me, with reference to the review of his book on “ Mental 
Development in the Child and the Race,” which was printed in the 
July number of the NATURALIST: 
“The very cordial and appreciative review of my book on Mental 
Development by Dr. Newbold in the July issue of this journal contains 
one remark which a word from me may serve to throw light upon. 
Dr. Newbold says that I sometimes ‘rest content with a careless and 
inadequate analysis of the psychoses which are to be explained.’ This 
is no doubt just, as far as the actual contents of my book are concerned, 
and as far as the word ‘inadequate’ goes. But I may say that the in- 
adequacy is due to the fact that I have already devoted my large 
Handbook of Pyschology—especially the second volume on Feeling and 
Will—to the detailed analytic treatment of the same functions which 
are treated genetically in the present book. I did not feel justified in 
doing that a second time. And moreover many of the analytic results 
which my Mental Development assumes are, I venture to think, such 
common property of psychologists to day that they are largely outside 
the arena of debate: at least, whenever my developments in this book 
seemed to me to turn on points in dispute, I tried not to leave the jus- 
tification of them in an inadequate state. I hope it is not too much to 
ask of readers that they bring their general psychology with them. It 
is really not the psychology that I fear the inadequacy of as much as 
the biology of the book, but however that may be, the omissions are 
well-considered and not ‘ careless. ”—J. Mark BALDWIN. 
1 This department is edited by Dr. Wm. Romaine Newbold, University of Penn- 
sylvania. 
