Periodical Literature. 303 



Althougli it may be tme that plants are able to lift water to 

 the leaves through comparatively short lengths of deadened 

 stem (considerably less than 30 feet), it has never been shown 

 conclusively that the living cells of the stem of tall plants are not 

 essential to transpiration. Root pressure, capillarity, and the 

 sucking action of the parenchyma of the leaves undoubtedly play 

 important roles in the ascent of water in plants. But a careful 

 study of the anatomy and morphology of plants indicates that the 

 living cells of the stem also perform an important function in tall 

 plants. 



"Relation of the Living Cells in Plants to Transpiration and Sap Flow." 

 Rot. Gazette, Vol. LI, No. 2, February, pp. 102-120. 



I. W. B. 



Cowles gives an interesting account of the 



Causes development of the study of dynamic plant 



of geology, and defines in a general way the 



Vegetative more important vegetative cycles and the 



Cycles. factors which control them. Vegetative 



cycles are shown to vary greatly in their 



duration. Thus climatic variations produce vegetative cycles 



wliose duration must be computed geologically. Within this 



climatic circle are cycles of erosion, each with its vegetative cycle. 



The general trend of such a cycle can be seen by studying the 



erosive process of to-day, by comparing the stages of one district 



with those exhibited in another. Within the cycle of erosion are 



many vegetative cycles, some so short that their stages may be 



studied from year to year in a given district. 



"The Causes of Vegetative Cycles," by H. C. Cowles, Bot. Gazette, Vol. 

 LL No. 3, March, pp. 61-183. 



I. W. B. 



SOIL, WATER AND CLBIATE. 



A study on the relation of soil and yield was 



5*0^7 made by Schoenberg in the pineries of the 



and forest school at Eberswalde, which contain. 



Yield. in sequence from one terrace to another, the 



five site classes usually recognized for 



pine — diluvial sand soil of varying character. It is interesting to 



note that proceeding in one direction from the plateau to the River 



