No. 440.] NOTES AND LITERATURE. 



565 



of the various physiological processes will be given, and such a posi- 

 tion may also be regarded as an excellent one. Too great conseiva- 



the style may readily become unsuggestive and the other is that these 

 very same "safe views" may become almost dogmatic. After an 

 introductory chapter on the general problem of physiology the ques- 

 tion of respiration is at once entered into and with it the correlated 

 phenomena of fermentation. There may be some who would be 

 inclined to doubt the entire wisdom of at once plunging into these 

 complicated matters, before the student has been informed of what is 

 known as to how or where the materials concerned in respiration are 

 produced. This is especially true of the subject of enzyme action, 

 and as a consequence the handling of this important topic is hardly 

 satisfactory. 



The space devoted to it is chiefly taken up with a consideration of 

 yeast fermentation, and the great classes of intra-cellular enzymes 

 are scarcely mentioned. The third chapter is on Nutrition and in 

 the next, absorption of water and food is treated of. Here for the 

 first time the fundamental question of osmosis is explained. The 

 different, necessary chemical elements, are taken up in turn. In 

 passing it may be mentioned that the literature quoted does not 

 always include the latest contributions to the subject, by the authors 

 named. The fifth chapter is devoted to the consideration of the 

 primal phenomena of growth, and following it is a long one, entitled 

 Irritability, under which head all growth responses, as well as the 

 movements of nature organs, are taken up. As an example of 

 unfortunately dogmatic statements may be mentioned the following, 

 which is given as an explanation of phototropism : " The cells on the 

 side of the stem away from the window receive less light and are 

 less checked than those on the opposite side, and hence push the 

 tip of the stem over towards the window." Such a definite explana- 

 tion, on the basis of etiolation, as the cause of phototropic curvature 

 would not be accepted by many physiologists, and is perhaps too 

 "safe" a view to take of this perplexing response. Attention may 

 also be called to the fact that the familiar term, etiolation is not used 

 at all by the author, and that the term heliotropism is preferred to 

 the generally admitted better one, phototropism. The last chapter 

 deals in the compass of thirty pages with the subject of reproduction, 

 including a three and one half page consideration of the problems 

 connected with heredity. The index leaves something to be desired, 

 not infrequently one must look in vain for references to familiar 



