Periodical Literature. 517 



cycle of weight production which is exhibited through the season 

 by those trees who do not form these autumn shoots. There is, 

 however, a variation in detail : while in the spring as regards 

 potash and phosphoric acid absorption is negative and of nitrogen 

 unusually large, after the autumn shoot the former culminate and 

 nitrogen becomes almost nil. Lime and magnesia behave exactly 

 opposite. The analyses also show that the early foliage is im- 

 poverished to furnish the materials for the autumn shoot. 



Die Penodizitdt der Ndhrsahaufnahme mid Trockensubstansbildung 

 von sweij'dhrigen Buchen. 



Zur Periodizit'dt der Stoffbildung mid Ndhrstoffaufnahme in jungen 

 Lauhholcern. 



Naturwissenschaftliche Zeitschrift fiir Forst-und Landwirtschaft. April- 

 May 1912, pp. 161-199. 



That the fall of leaves, which is an annual 



Causes occurrence in the temperate climates is even 



of here not due to external conditions alone has 



Leaf -fall been shown by Dingier. Observations on 



trees in Ceylon which regularly shed their 



leaves (17 species out of 280) show that they lose their leaves 



mostly in January or February, shortly before the dry hot season 



of Februay and March, sometimes as early as December. In 



April they bud again. Trees pruned in October in the botanical 



garden, however, retained the newly formed foliage through the 



dry period, and even in May were still in full foliage, while all 



the specimens of the same species which had not been pruned 



lost their foliage and remained naked during the dry season. 



From this again the deduction is made that the exterior conditions 



w^hich the dry season brings is not the immediate cause of the 



normal leaf-fall of these trees. 



From Naturwissenschaftliche Rundschau in Centjalblatt f. d. g. Forst- 

 wesen April 1912, p. 196. 



Wehmer amplifies his brief 1910 article on 

 "Cellar- this subject by a comprehensive description 



Fungus' of the development peculiarities of Conio- 



Coniophora phora cerehella A. & S. as compared with 

 Cerehella other wood-destroying fungi found in build- 



ings. ■ He shows that the ability of Conio- 

 phora to produce abundant aerial mycelium in unventilated places 

 is a diagnostic character of the fungus. When a culture in an 



