85 



dentata, Plataniis occidentalis, Magnolia virginiana, Cebatha Caro- 

 lina, Philadelphus inodorus, Pcrsea horbonia, Sassafras officinale, 

 Gaylussacia dumosa, and Viburnum alnifolium. All of these plants 

 are still thriving species although three of them no longer range 

 this far north. But the Pensauken rocks were laid down during 

 an interglacial period of the Pleistocene, or perhaps before the 

 Jerseyan glaciation. 



BOOK REVIEWS 



Basic Course in Botany* 



J. W. Thomson, Jr. 



The aim of this new addition to the ever-increasing list of text- 

 books in general introductory botany is an attempt "to emphasize 

 the essentials of science, and especially the broad, biological point 

 of view, more consciously and persistently than is done in similar 

 works." To achieve this aim, the first two chapters are devoted 

 to "the point of view" and "biological fundamentals," and through- 

 out the book an introduction to each topic stresses generalizations 

 which are then discussed in greater detail. 



In general content the new text is similar to previous texts. 

 After a consideration of plant cells and their activities, the tissues 

 and organs of the plant ; roots, stems, leaves, flowers, fruits and 

 seeds are taken up. The activities of the organs are discussed in 

 the same chapters as the structures. Following the chapters upon 

 anatomy and physiology, the plant kingdom is well covered in eight 

 chapters. The chapters "plants and their environment" and "plant 

 communities and vegetation regions" give, as would be expected 

 from Dr. Pool, a better consideration of plant ecology than many 

 other general texts. These chapters are limited to North American 

 vegetation. Pathology and heredity and evolution are also given 

 chapters. 



While some of the diagrams intended to simplify general prin- 

 ciples seem unnecessarily complicated, and some of the photographs 



* Basic Course in Botany. Raymond J. Pool, v -f- 654 pages. Ginn and 

 Co. 1940. $3.75. 



