﻿iqi6] CURRENT LITERATURE 81 



neither cytolytic nor toxic activity, nor did it contain any trace of oxalic acid 

 or oxalates to which the toxic action of Botrytis extract has sometimes been 

 attributed. The enzyme acts only in acid media. In neutral solution its 

 activity is greatly retarded, and in slightly alkaline media the activity is 

 inhibited. Here again the toxic properties of the extract are affected in the 

 same manner as the cytolytic properties. The extract may be reactivated 

 by the addition of acid to the neutralized or alkaline medium. From the 

 impossibility of separating, by any of the means described above, the toxic 

 and the cytolytic properties of the extract, the author js inclined to believe 

 that both are due to the same substance or group of substances. 



The most striking difference in the physiological behavior of these two 

 fungi is seen in the extent of their cytolytic action. By reason of its greater 

 virulence in this respect, Botrytis cinerea is adapted to live as a saprophyte on 

 dead plant tissues poor in soluble carbohydrates, while Monilia, possessing 

 the power of hydrolyzing cellulose only to a slight extent, is restricted in its 

 existence to ripening fruits and other tissues rich in soluble sugars. Correlated 

 with this difference in the mode of life of the two fungi is the method of produc- 

 tion of sclerotia. The tissues invaded by Botrytis are completely destroyed, 

 consequently the sclerotia are formed as well defined free bodies outside of the 

 invaded substance, while in Monilia the sclerotia are formed within the mum- 

 mified tissues of the host, which are sometimes involved in the process. — H. 

 Hasselbring. 



Notes on gymnosperms.— Thomas* has discovered the staminate strobilus 

 of Williamsonia gigas from the Jurassic of Yorkshire. The strobilus consists 

 of 18-20 microsporophylls united into a cuplike structure. Thomas is inclined 

 to believe that these sporophylls were not associated with the ovule-bearing 

 region, but that they represent an independent staminate strobilus. 



Sahni" has discovered in the pollen chamber of some young ovules of 

 Ginkgo certain winged pollen grains which are very different from those of 

 Ginkgo. About a dozen such ovules were examined, and 8 contained these 

 foreign pollen grains, characterized by prominent wings. Furthermore, not 

 only did these ovules contain foreign pollen from as many as three distinct 

 species, but one of the pollen grains was in an advanced stage of germination. 

 The interesting suggestion is made that if a similar example were found in a 

 fossil, "it would in all probability lead to a reference of the pollen grains and 

 ovules to the same species." Since this has been done already, the caution is 



s Thomas, H. Hamshaw, On some new and rare Jurassic plants from Yorkshire: 

 the male flower of Williamsonia gigas (Lind. and Hutt.). Proc. Cambridge Phil. Soc 

 18:105-110. pi. 6. figs. 2. 1915. 



6 Sahni, Birbal, Foreign pollen in the ovules of Ginkgo and of fossil plants. 

 NewPhytol. 14:149-151. pi. 2. 1915- 



