181 



wise sharper outlines as to venation and reticulations will usually 

 be secured if the lower surface of the leaf be selected in prefer- 

 ence to the upper. In selecting leaves for outlining care must 

 be taken not to injure the specimen, especially if it is a type. 

 Wrinkled or very brittle leaves should never be selected, and 

 care should be taken to avoid those that are so mounted that 

 they might be broken if rubbed too hard. 



About eight years' use of these carbon rubbings or impressions 

 has thoroughly convinced me of their practical utility in her- 

 barium work. Several European botanists to whom I explained 

 the simple method of making the carbon rubbings were at once 

 impressed with the utility and advantages of the method and 

 have adopted it in their regular herbarium work. The advantages 

 of the method are so great, the technique so simple, and the 

 preperation of the impressions or rubbings so rapid, it is believed 

 that rapidity, accuracy, and ease in certain lines of routine her- 

 barium work will be greatly enhanced by the general utilization 

 of this simple method. The illustrations accompanying this 

 paper are reproductions of carbon rubbings or impressions, not 

 at all retouched, prepared by the method described above. 

 Washington, D. C, 

 July 15, 1915- 



REVIEWS 



Cowles and Coulter's Spring- Flora* 



The purpose of this flora, as stated by the authors, is "to 

 provide, especially for young people in high schools, a ready 

 means for the identification of the more common and widespread 

 spring flowering plants." Descriptions are given of 380 plants 

 which flower before July in the North Central and Eastern States 

 and there is a single comprehensive key to the various species 

 treated, based on such characteristics as are readily observable 

 in spring. The work is illustrated by nearly 150 drawings. 



As an introductory guide for the identification of the spring 

 flowering plants in the area covered it is difficult to see how this 

 little book can be improved upon. One notes with some surprise, 



* Cowles, H. C and Coulter, J. G. A Spring Flora for High Schools. Pp. 

 1-144. American Book Co. 1915. 



