NOTES AND COMMENT 177 



Dr. H. C. Cowles and Dr. J. G. Coulter have issued a small manual 

 of the spring flora of the north central and northeastern states (Ameri- 

 can Book Company). The book has been adapted to high school 

 use by the omission of grasses and other difficult groups, and by the 

 prefixing of a very simple analytical key. Trees, shrubs, and other 

 plants of importance in ecological work have been included, and are 

 described and illustrated in their spring condition. 



Mr. B. C. Wallis has made a study of the rainfall conditions of the 

 southeastern states in relation to the production of the cotton crop 

 (Scottish Geographical Magazine, February, 1915). Cotton is grown 

 in localities which vary in annual rainfall from 54 inches at the east 

 to 31 inches at the west, but the crop is timed in such a manner that 

 the precipitation during the growth of the cotton plant varies only 

 from 17 inches in Texas to 23 inches in Florida. 



The Monthly Weather Review for October 1914 contains a paper 

 by Prof. W. J. Humphreys on frost protection, a paper by Prof. C. F. 

 Marvin on the principles of air drainage, and several articles that 

 describe the methods and results of extensive efforts that are made 

 for the protection of orchards from frost in California, Ohio and other 

 states. 



