800 



SCIENCE. 



[N. S. Vol. XII. No. 308. 



SCIENTIFIC BOOKS. 

 Die Elemente der Eniivickelungslehre des Menschen 



und der Wirhelthiere. Vou OSOAE Hertwig. 



Jena, Gustav Fischer. 1900. 8vo. Pp. vi + 



406, mit 332 Abbildungen im Text. 



This work is an abbreviated reissue of the 

 author's well-known ' Lehrbuch ' — the new 

 work being about one-third the size of its par 

 ent. There is otherwise exceedingly little 

 change, for there is no important modification 

 of the general plan or of the style of treatment 

 or in the point of view from which the author 

 treats his subject. There has been no effort at 

 all to recast the work so as to render it more 

 suited to the requirements of embryological 

 study in the laboratory. The text is taken from 

 the ' Lehrbuch,' with here and there modifica- 

 tions of the phraseology, and with connecting 

 new short parts to supply the place of some of 

 the elided portions. The figures are nearly all 

 from the 'Lehrbuch.' 



Those who are familiar with the larger text- 

 book will therefore have a very good con- 

 ception of the character of the new volume and 

 will find again the familiar merits and defects. 



The author has been one of the foremost of 

 embryological investigators, confining, how 

 ever, his original researches to a few fields. 

 On such topics as the history of the genital 

 products he writes with full mastery of the sub- 

 ject, and his fine gift for the understanding of 

 morphological problems, and his rare ability as 

 an expositor, have combined to render all such 

 parts of the volume of the very highest excel- 

 lence. Unfortunately he seems to have been 

 indifferent to the study of many other aspects 

 of embryological study, and to have been satis- 

 fied with a somewhat vague aquaintance with 

 many important parts of the science. This 

 general defect shows very strongly in tlie ab- 

 sence of original illustrations, and in the fact 

 that a large proportion of the minority of orig- 

 inal figures are diagrams. Of these diagrams 

 some are strangely incorrect, as, for instance, 

 those of the development of the middle germ 

 layers and those of veins. These diagrams indi- 

 cate developmental processes, which are diamet- 

 rically opposed to the observed facts. Equally 

 unfortunate are his diagrams of the fcetal en- 

 velopes in birds and in mammals, since they are 



in part quite erroneous. As some of the figures 

 are copies after inaccurate originals, there is 

 need for still further revision : thus in Fig. 144, 

 the amnion and chorion are wrongly repre- 

 sented, and the epithelium of the chorion is not 

 only misdrawn but is labeled decidua reflexa. 

 There are in the text also deficiencies which 

 would certainly be corrected if the author's 

 study of the embryonic conditions were made 

 to a larger degree at first hand, for example, 

 and notably in the case of the liver, the veins, 

 the thymus, the pharynx and its appendages, 

 the brain and certain other parts. 



But though one may regret these and other 

 deficiencies, some of which are very difficult to 

 excuse, it remains true that the book deserves 

 far more praise than fault-finding, and it ought 

 to have a generous and hearty welcome, so that 

 further editions may be called for soon, in 

 which the author will have an opportunity to 

 make the much-needed improvements. It is 

 with regret that the reviewer finds himself 

 obliged to qualify his recommendation of a 

 work which he has found very helpful and 

 stimulating. ^ g_ j^^^^^_ 



Studies of American Fungi : Mushrooms, Edible, 

 Poisonous, etc. By George Francis Atkin- 

 son, Professor of Botany in Cornell Univer- 

 sity, and Botanist of the Cornell University 

 Agricultural Experiment Station. Andrus & 

 Church, Ithaca, N. Y., U. S. A., publishers. 

 8vo. Pp. i-vi, and 1-275, with 76 plates 

 and over 150 text illustrations. Price, $3.00, 

 postpaid. 



In the publication of this book, which has 

 just come from the Genesee Press, Rochester, 

 N. Y. , it seems desirable that the author should 

 call" attention to some of its features, the im- 

 portance of which might at first be overlooked. 

 In this connection it may not be out of place to 

 first make some general statements regarding 

 the book, a few of which are adapted from the 

 introduction. 



Since the issue of my ' Studies and Illustra- 

 tions of Mushrooms,' as bulletins 138 and 168 

 of the Cornell University Agricultural Experi- 

 ment Station, there have been so many inqui- 

 ries for them, and for literature dealing with a 

 larger number of species — it seemed desirable to 



