136 General Notes. [February, 



Kuetz. accompany " Notes on British Characes " by H. and J. 

 Groves in the December Journal of Botany. The two delayed 



plates illustrating a paper on Cine ho u 1 Led^erian ■ (from Bolivia), 

 by Henry Trimen in the November Journal of Botany, appear in 

 the December number. They are excellently done. 



ZOOLOGY. 



IS THE HUMAN SKULL BECOMING THINNER ? If the doctrines of 



evolution are true, and the evidence supporting them is of a con- 

 vincing character, questions relating to the operation of the laws 

 by which improvement or degradation results, become of particu- 

 lar importance when applied to the human race, and it is a matter 

 of serious inquiry whether, under the altered conditions of 

 civilization, causes may not be at work which operate to the dis- 

 advantage of the whole organism, by detracting from the efficiency 

 of a part ? 



According to the theory as expounded by Darwin and others, 

 we have the tendency of all organisms to accommodate themselves 

 to their environment, and to adapt themselves to altered circum- 

 stances within certain limits, this principle of adaptation in co- 

 operation with heredity, or the tendency of the offspring to in- 

 herit the characteristics of its progenitors, are made to account for 

 much of the otherwise inexplicable phenomena with which we 

 are surrounded. 



Now according to this doctrine, an organism is endowed with 

 ability to succeed amid certain surroundings — in the higher verte- 

 brates, for example, we have the framework of bone, with all its 

 beautiful applications of the principles of mechanics, so arranged 

 as to prevent to a great extent injury of the important organs, 

 and when we come to the brain, we find it enclosed in a rigid 

 covering, capable of resisting a considerable degree of violence 

 without being fractured, and evidently intended to protect the 



If we accept the tenets of evolutionists, a race adapted to cer- 

 tain circumstances, will, if those circumstances be altered, become 

 modified in a corresponding degree, and retrogression may result 

 as well as improvement, and this modification may be confined to 

 a certain part or organ. Let us consider, therefore, what forces have 

 exerted their influence upon this casket of the brain. 



First, natural selection in the case of those creatures that en- 

 gaged in fierce combats, would lead M eliminate those individuals 

 with frail craniums, and as man comes within the category oi 

 belligerent creatures, when barbaric warfare, and the dangers of 



of course exercise a powerful, influence in maintaining a standard 

 of cranial strength. Then, too, in the presence of repeated violence, 

 adaptation would undoubtedly provide a suitable armor for this 

 delicate and important organ. And as it is difficult to conceive 



