July 14, 1911] 



SCIENCE 



55 



mine by a study of specimens in captivity 

 whether a lizard is herbivorous or insectivo- 

 rous, but from such data it is not possible to 

 determine the range of diet, and generally 

 impossible to work out at all satisfactorily 

 the habitat preferences, reproduction, etc. It 

 may readily be seen that this is true by an 

 examination of this book, for it is the food 

 that captive specimens will take that is given 

 in most of the accounts of feeding habits, and 

 habitat preference and reproduction come in 

 for very brief treatment. The author might 

 very profitably have included sunnnaries of 

 the published notes on the habits in nature. 

 On the other hand, it is only just to acknowl- 

 edge that the observations on the habits of 

 specimens in captivity are of value, not only 

 to those who wish to keep live material but 

 also to scientists, for even general informa- 

 tion is desirable in the case of many forms. 

 Thus, on the basis of his observations on 

 captive animals, Ditmars refutes the often 

 repeated statement that the iguanas (sub- 

 family Iguaninse) and Basiliscus are strictly 

 herbivorous (that they are also insectivorous 

 in nature is a fact that may easily be demon- 

 strated by an examination of the stomach con- 

 tents of wild individuals), and the observa- 

 tions on the breeding habits of Elaps fulvius 

 and Lachesis mutus are distinct contributions 

 to our knowledge of the habits of these 

 species. 



In some respects the book-making is very 

 good. There seem to be very few typograph- 

 ical errors. The upper figure on pla.te 3 is 

 upside down, and in the table on p. 100 the 

 genus Coleonyx is placed under the family 

 TJroplatidse by a printer's mistake. But these 

 are very unimportant errors. The most un- 

 fortunate thing about the book from this 

 standpoint is the absence of appropriate 

 headings. The book is divided into four 

 " parts," dealing with the turtles, crocodiles, 

 lizards and snakes, respectively, but aside 

 from this division there are no subdivisions 

 of the subject matter, if we except the fact 

 that there are center heads to the sections on 

 the structure of lizards, the family Boidee, 

 and the new world Elapine snakes. The 



names of the families considered are usually 

 given as side heads and the common names 

 given to families when used as side heads and 

 the common names of the genera and species 

 when beginning a paragraph are placed in 

 small capitals, but this is not sufficient to 

 break up the text conveniently, and it is very 

 difficult to find the descriptions of particular 

 forms. The author states that " the scope of 

 the book prevents it from being, as a previ- 

 ous book [' The Eeptile Book '] by the same 

 author was, primarily a volume for identifica- 

 tion purposes," and it is probably for this 

 reason that the excellent arrangement of the 

 former work was not followed, but the value 

 of the book could have been greatly increased 

 by the use of at least a general system of 

 headings, such, for example, as the one em- 

 ployed in Knowlton's " Birds of the "World." 

 Another fault in the arrangement is that the 

 plates are not referred to in the text, and, as 

 they are often far removed from the descrip- 

 tions of the species, they can not be con- 

 veniently found. 



One may, however, easily overlook the de- 

 fects in the book for it is a valuable contri- 

 bution to the subject. It is a good popular 

 account, as the author intends it to be, and at 

 the same time it will find its place on the 

 shelves of the general zoologist and herpetol- 

 ogist, both for its very excellent illustrations 

 and for the information on habits that it con- 

 tains. 



Alexander G. Euthven 



Natural Vegetation as an Indicator of the 

 Capabilities of Land for Crop Production 

 in the Great Plains Area. By Homer Le- 

 ROY Shantz, Physiologist, AU^ali and 

 Drought Eesistant Plant Breeding Investi- 

 gations. Bulletin 201, Bureau of Plant 

 Industry, IT. S. Department of Agriculture. 

 Washington. 1911. Pp. 100; 6 plates and 

 23 text figures. 



This first endeavor to apply the exact meth- 

 ods of quantitative ecology to the problems of 

 agriculture meets with conspicuous and 

 gratifying success. The author is as skilKul 

 as thorough in his use of instrumental and 



