252 The Plant World. 



and Riibel has accomplished these ends ^\ith conspicuous suc- 

 cess. An attempt to draw from these two sets of facts some 

 inferences regarding the relative weight of the several factors, 

 and the critical points in their operation, as related to the 

 controlling of plant occurence and the distribution of the associa- 

 tions involved, is a still more difficult undertaking. It can only 

 be regretted, however, that Riibel has not made this additional 

 ttep. He has given an admirable presentation of two great sets 

 of facts without making any attempt whatever, in the present 

 paper, to correlate them. — F. S. 



NOTES AND COMMENT. 



The entrance of any person into science in a serious manner 

 is usually connected with the woik carried out during his can- 

 didacy for the doctor's degree, and the details of the 437 doctor- 

 ates granted by American Universities in 1911, may be taken 

 to indicate with considerable probability the character of the 

 life-work of the botanists included. 



Twenty theses are credited to departments of botanical 

 fcience, but as nine others in agriculture and bacteriology are 

 so fundamentally botanical, they are included in the following 

 list extracted from the original article. * 



Charles Orval Appleman: "Some Observations on Catalase.'' 

 (Chicago). 



Grace Miriam Charles: "The Aantomy of the Sporeling of A/afa«»a 

 alata." (Chicago). 



William Skinner Cooper: "The Climax Forest of Isle Royale, Lake 

 Superior." (Chicago). 



Thomas Haigh Glenn: "Variation and Carbohydrate of Bachilli of 

 the Proteus Group." (Chicago). 



Mary Sophia Young: "Morphology of the Podocarpineae. " (Chi- 

 cago). 



Le Roy Abrams: "A Phyto-geographical and Taxonomic Study of 

 th Southern California Trees and Shrubs." (Columbia). 



Ralph Curtiss Benedict : ' ' The Genera of the Fern Tribe Vittarieae. ' ' 

 (Columbia). 



Frank Dunn Kern : " A Biologic and Taxonomic Study of the Genus 

 Gmynosporangium." (Columbia). 



Alvin Carey Beal: "A Study of the Genus Lathyrus." (Cornell). 



George John Bouyoucos: "Transpiration of Wheat Seedlings as 

 •Doctorates conferred by American Universities. Science. 34: 193. 1911. 



