October 25, 1907] 



SCIENCE 



547 



tion. The volumes before us are singularly 

 fiee from all attempts to draw far-reaching 

 coiiclusions from insufficient data. 



The publication of this work marks an 

 epoch in the history of double-star astronomy. 

 It becomes at once an authoritative exposition 

 of the state of the sky in respect to the class 

 of objects it considers, and a reference that 

 will take the place of hundreds of publica- 

 tions. No single work has been more press- 

 ingly needed these many years, and none 

 could have filled the requirements of practical 

 observers and of astronomers generally more 

 satisfactorily. It will be an instrument of 

 progress, leading and directing; an example 

 to be followed, not only in its own field, but 

 also in other departments. 



W. J. HusSEY 



Ann Arbob, Mich., 

 September, 1907 



The Frog Book: North American Toads and 

 Frogs, with a study of the habits and life- 

 histories of those of the Northeastern States. 

 By Maey C. Dickerson. New York, 

 Doubleday, Page & Co. 1906. Pp. 253. 

 $4.00. 



This book is the twelfth volume in that 

 noteworthy series " The Nature Library." In 

 it we find a most satisfactory solution of the 

 difficult problem of how to make a popular 

 book really good, although of large size and 

 about a group of animals that is not a large 

 group and is less attractive to the layman 

 than birds, fish or insects. 



Like others in the series, it is profusely 

 illustrated with original photographs, some 

 290 of them in 96 plates and 30 in text figures. 

 Most of these show the living frogs and toads 

 exceedingly well in black and white, while 16 

 plates are nicely colored. Some of the text 

 figures are merely embellishments and twelve 

 plates are photographs of attractive scenery 

 representing the haunts of frogs. 



The text begins with an introduction of 

 40 pages. With this is an artificial key for 

 finding out the names of all the frogs and 

 toads throughout the United States. 



The main part of the work is a description 



of the 56 frogs and toads of this country taken 

 up in systematic order in their seven families 

 and twelve genera. The common toads, their 

 eggs and young, are well treated and their 

 value to agriculture emphasized, but the prac- 

 tical side of the subject is not exaggerated and 

 the author's real interest in nature is ex- 

 pressed in such sentences as : " We also find 

 the toad's song one of the most beautiful 

 sounds in nature. The effect of a 'chorus' 

 of toads is harmonious indeed — a crooning 

 sound that seems a fit companion for amorous 

 spring, bursting flower buds and the feeling of 

 new life in our hearts." 



Some thirty-six pages of text and many of 

 the well-colored and spirited illustrations of 

 the book well represent the tree-frogs; one of 

 which on a " Jack-in-the-pulpit " makes the 

 charming frontispiece. Here as elsewhere 

 there are suggestive new facts, such as the 

 statement that some tree-frogs of the species 

 Hi/la squirella, shut in a pail with no change 

 of condition, continued for some hours to 

 change their colors; which of course empha- 

 sizes the fact that color changes in frogs may 

 be brought about without light or other out- 

 side cause. 



The descriptions of the common larger frogs 

 of our ponds, woods and meadows take up the 

 remaining seventy pages of the volume, which 

 ends with a bibliography of one hundred titles, 

 embracing such diverse works as Wieders- 

 heim's "Anatomy" and White's "Natural 

 History of Selborne." 



Not only are the habits of the common frogs 

 well portrayed, but the eggs and tadpoles are 

 figured, as has not been done before, and 

 throughout the work the author's genuine sym- 

 pathy with nature is in evidence. The nat- 

 uralist will be glad to have the pictures in this 

 book accessible and the layman should find 

 the book both attractive and useful, while 

 school nature-study could make excellent use 

 of it. 



The large amount of original observation 

 made by the author will best be appreciated 

 by those whom the book should stimulate to 

 add more to the facts accumulating towards 



