432 



SCIENCE 



[N. S. Vol. XXXIII. No. 846 



Blood Eelations, Parasitism, Grafting, Se- 

 nescence and Mutilation and Regeneration. 

 When it is considered that more than nine 

 tenths of the students taking the course in 

 beginning biology go no farther in that de- 

 partment, we come to realize that our course 

 should be so shaped that this great majority 

 receive the consideration, and not the few 

 who later become students in higher courses. 

 It is for this reason, if for no other, that 

 the economic side of the subject is war- 

 ranted. Not that this be overdone. There is 

 a danger that our references become so anthro- 

 pocentric that we shall need another Galileo; 

 man must be kept in his proper relation with 

 the universe at large, and bacteria, moulds, 

 pathogenic protozoa and antibodies must be 

 seen to be part and parcel of this universe and 

 not designed as helpers or scourges of man- 

 kind. 



There is in this book a laxity in attention 

 to details that will be "discovered by the care- 

 ful reader. Eegeneration and continuous 

 growth are two different things, although the 

 author treats them as one. Mitosis precedes 

 the appearance of the bud in the growing yeast 

 and not vice versa. The granular theory of 

 protoplasmic structure is not generally con- 

 ceded. The figure of a typical cell, copied 

 from Huber, is wretched and misleading. But 

 it is easy to tear down and hard to construct. 

 The book is inspiring to the student who looks 

 broadly at the subject and one wishes it were 

 more adapted to the needs of the modern 

 American boy. 



Hegner" has designed his text to occupy the 

 first half year of a course where the second 

 half year is devoted to vertebrate zoology. 

 But it is not, sensu strictu, an invertebrate 

 zoology. It falls in our category, 2a, being a 

 biology with especial reference to inverte- 

 brates. The attempt is made to present the 

 newer zoology to the beginner. Here we find 

 the figures of Jennings, Yerkes, Morgan — in 

 fact it may be called an American product 

 from cover to cover. Consequently, the stu- 

 dent finds himself at home at once among 



" " An Introduction to the Study of Zoology," 

 Macmillan, 1910. 



American forms and American names. It is 

 not to be understood, however, that the view 

 is circumscribed and that the data from for- 

 eign sources are eliminated. 



Leaving aside for the present time the value 

 of introducing the student directly to the un- 

 seen world of the protozoa, it may be said 

 that the result is excellent in the light of the 

 labor set before its author. The book-making 

 is good, the illustrations are carefully selected 

 and there is a unity in the volume which ap- 

 peals very strongly to the reviewer. There are, 

 as before, places where changes in future edi- 

 tions may be suggested. It is discouraging to 

 the student to be introduced to pages of 

 Greek and Latin terms at the outset. Sufficient 

 unto the later pages is the evil thereof; let 

 us not blunt his zeal at the start. The descrip- 

 tion of photosynthesis is so involved with that 

 of respiration that the average student will 

 not untangle them, and when the statement is 

 made that " one group of processes (respira- 

 tion) uses the waste products of the other 

 (photosynthesis)" the error is obvious, for 

 while this may be so for a part of the time, the 

 relation does not exist at others (in darkness). 

 As Professor Alexander Petrunkevitch has 

 pointed out, the figure from Dahlgren and 

 Kepner illustrating the alveolar hypothesis of 

 protoplasmic structure is wrong, inasmuch as 

 this theory involves a foam structure and not 

 that of an emulsion. Amitosis should not be 

 given the prominence that it enjoys in the 

 book, whatever the personal views of the au- 

 thor, for the statements are not warranted by 

 recent investigations. Moreover, the selection 

 of Wheeler's drawings of amitosis in the fol- 

 licles of the insect ovary to illustrate ami- 

 tosis as a process of cell-multipKcation is not 

 fortunate, inasmuch as there is only nuclear 

 and not cytoplasmic division. Maupas's 

 schema of the effects of isolation from conju- 

 gation in Paramecium is given, although the 

 text states, rightfully, that the work of Wood- 

 ruff and others, such as Gregory and Jen- 

 nings, has led to a different interpretation. 

 Schultze's figures of the development of the 

 sponge are adopted, although there is perhaps 

 nowhere in biology a more difficult bit of 



