BOOKS AND WRITERS 



"Heredity and Evolution in Plants" by C. Stuart Gager, 

 is a re-issue of several chapters from the author's earlier vol- 

 ume "Fundamentals of Botany" together with additional new 

 chapters on the distribution of plants, the whole making an 

 attractive presentation of the subjects included in the title. 

 Although the simpler plants are frequently mentioned, the dis- 

 cussion really begins with the structure and evolution of the 

 fernworts and the higher plants receive the greater share of 

 attention. The chief concern of the book is the methods by 

 which plants have come to have their present forms. The 

 prol)lems of hereditv are explained and much space, of course 

 is given to the Darwinian and Mutation Theories, the experi- 

 mental study of heredity and evolution, and the distribution of 

 plants in time and space. The latter phase of the subject is 

 of especial interest, though frequently omitted from similar 

 books. The clearness of the text is one of its chief recom- 

 mendations. There are a number of unique and modern illu- 

 strations and the book as a whole can be recommended to any- 

 one desirous of a concise explanation of plant evolution. It is 

 published by P. Blakiston's Son & Co., Philadelphia. 



Although the entire annimal world subsists upon plants, 

 poisonous species seem to be the rule rather than the exception. 

 Even some of our food and beverage plants contain poisons as 

 for instance chocolate and coffee. Usually, however, the poi- 

 sons are present in such minute quantities that they are realiv 

 harmless; indeed, several of the plants most frequently used 

 owe their chief value to these substances. A number of com- 

 mon plants are well known to be poisonous and are shunnedi 

 accordingly, but many others, seldom regarded as noxious maj- 



