^6 THE PLANT WORLD. 



I notice under " Notes and News" in the December number of 

 the Plant World, a note relating to the branches falling from the 

 Cottonwood, and the conclusion that this was a device for multiplying 

 and spreading the species. Several years ago the attention of the 

 Philadelphia Botanical Club was called to the dis-articulation of the 

 branches of the Cottonwood {Populits monifera) and also of the White 

 Oak [Qiiercus alba) by that observing botanist, Benj. Heritage of Mick- 

 leton, N. J. The conclusion reached was: that this was a provision of 

 nature to dispose of the now unnecessary branchlets and without leaving 

 a knot. When a boy, there stood in my father's yard a large White Oak 

 tree, which in the fall, cast a large quantity of these dis-articulated twigs. 

 We thought then, as now, that it was a way of self-pruning and with- 

 out leaving a knot to decay. With the Cottonwood, these twigs might 

 grow, under favorable circumstances, but it is not likely that those 

 from the White Oak would. — C. D. Lippincott, Swedcsbo7'o, N. J. 



. . . Bo on REVIEW S . . . 



Reference List of Publications Relating to Edible and Poisonous 

 Mushrooms. By Miss Josephine A. Clark. U. S. Department of 

 Agriculture, Library Bulletin No. 20. January, 1898. 



This is a valuable list of publications relating to a subject that is 



every day growing in importance. It may be obtained by application 



to the Secretary of Agriculture. 



Laboratory Exercises in Vegetable Physiology. By Dr. J. C. 

 Arthur. 8-vo; pp 32. Kimmel & Herbert, Lafayette, Ind. ; 35 cts. 



This little pamphlet contains full accounts of some thirty-five ex- 

 periments in plant physiology, being both qualitative and quantita- 

 tive work illustrating important phases of the subject. It is ade- 

 quately illustrated, and will undoubtedly be found of much value in 

 class-room work. 



Journal of the National Science Club, Washington, D. C. Jan- 

 uary, 1898; pp. 26. 



This appears to be the initial number of a journal that is to be , 

 the organ of the National Science Club, a club with headquarters 

 in Washington, D. C. It is, however, without a volume number, 

 although there are internal indications that it is to be a serial pub- 

 lication. There are three interesting botanical articles: "Leaf- 

 variation," by Mrs. W. A. Kellerman; ''The Ways of Climbing 

 Plants," by Mrs. Mary E. Treat, and "Edible Mushrooms," by Mrs. 

 E. C. Anthony. The publication seems to lack proper editorial 

 supervision. 



