118 THE PLANT WORLD 



Notes of Current Literature. 



In 1895, Dr. C. E. Waters, of Johns Hopkins University, published 

 an interesting and valuable key to the ferns of the Northeastern United 

 States based on a study of the stipes. It was designed solely as an aid 

 in identifying the ferns when they can not be obtained in fruit. The 

 author considers that his first paper was faulty in that it did not take into 

 account any but average sized specimens of the various species treated. 

 Dr. Waters has now prepared a careful revision of this key (John Hop- 

 kins University Circulars, No. 158, June 1902, pp. 83-85), in which very 

 large as well as very small-sized specimens of each species were studied. 

 The result is a very satisfactory key to our ferns, and one that must 

 prove of great value in placing the species when only sterile specimens 

 can be obtained. The primary divisions are based on the number of 

 bundles observed in a cross-section of the stipe, and the secondary 

 divisions on the shape and disposition of the bundles. Numerous cross 

 references make it possible to place large or small specimens of a species, 

 as well as the normal examples. Copies of the paper may be obtained 

 of the author for fifteen cents. 



It has been recognized for some time that various fungicides, espec- 

 ially such as contain copper, prove injurious in greater or less degree 

 to the foliage of fniit trees and other plants. Mr. S. M. Bain, of the 

 University of Tennessee, has conducted an extended series of experi- 

 ments on the Action of copper on leaves (Bull. Agric, Exp. Station, Univ. 

 Tenn., Vol. XV. No. 2, pp. 19-108, Vols. I-^Till), with special reference 

 to the injurious effects of fungicides on peach foliage. He finds that as 

 peach leaves have a thin cuticle they have the property of absorbing the 

 copper solutions and thus inducing injury to the growing cells. Lime 

 neutralizes or at least retards this injurious action. 



The Bureau of Plant Industry in the U. S. Department of Agricul- 

 ture has recently issued a number of bulletins, as follows : The North 

 American Species of Spartina, by E. D. Merrill [No. 9]; Records of 

 Seed Distribution, and Cooperative Experiments with Grasses and 

 Forage Plants, by F. Lamson-Scribner [No. 10] ; Johnson Grass, by 

 C. R. Ball [No. 11]; Experiments in Range Improvement in Central 

 Texas, by H. L. Bently [No. 13] ; Forage Conditions on the Northern 

 Border of the Great Basin, by David Grifiiths [No. 15]. Copies of these 

 bulletins may be purchased of the Superintendent of Documents, Union 

 Building, Washington, D. C. 



