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THE AMERICAN NATURALIST. [Vol. XXXVII. 



ZOOLOGY. 



Animal Classification. 1 — Teachers of elementary zoology but more 

 particularly students of this subject are often given to crave a simple 

 classification of animals, and to fill this want Professor Wilder has 

 prepared a synopsis of the chief animal groups. The author has 

 disarmed criticism by his avowal that schemes of this nature are 

 mainly personal, but even in such outlines it is fair to expect consis- 

 tency and freedom from obvious error. Presumably the part on 

 vertebrates should be best written and yet by a strange coincidence 

 the Vertebrata (p. 39) is the only type to which no general definition 

 is given, and the classes of its gnathostome division are numbered 

 one to six with the omission of four. There is no reason to suppose 

 that the beginner would ever rightly determine, by the artificial key 

 at the end of the book, the groups to which such forms as the 

 bilateral sea-urchins and holothurians belong, for by the tables these 

 must come under " Structure radiate." The statement that follows 

 this, " Parts in 2s " would be a stumbling block to any one who knew 

 what bilaterality was. On the whole this key is so very artificial 

 that it is best used when one knows beforehand where the animal 

 belongs. Defects of the kind pointed out, while of no great impor- 

 tance to the advanced student, are serious matters with the beginner, 

 and render the tables much less useful than they should be. 



Hertwig's Manual of Zoology. 2 — It is a remarkable fact that 

 Hertwig's Lehrbuch, the best German elementary text-book in 

 zoology, has been until recently accessible to the English-reading 

 student only through a partial and imperfect translation. Kingsley's s 

 new edition in English based on the fifth German edition will there- 

 fore be welcomed by many. A cursory examination of the new 

 volume shows that the American edition is likely to repeat the suc- 

 cess of its German forerunner. The translating is remarkably well 

 done and the general form of the book excellent. Here and there 

 exception may be taken to the course chosen by the translator. It 



cecology, which is coming to have a definite meaning, rather than the 



