1899] PHYLOGENY OF RUST 391 



which resembles in all other particulars one of the Lepto-forms inhabiting 

 Rhamnus. Fischer prefers the view that in this case the ancestral form 

 was capable of completing the whole cycle of its life-history, as well on 

 grasses as on various species of Rhamnus, and that its descendants 

 became specialised so as to form either aecidia on Rhamnus and the 

 uredo-teleutospore generation on grasses, or the aecidia was dropped 

 and the uredo-teleutospore generation alone persisted on Rhamnus as in 

 the Leptopuccinias in question. 



As, however, these give rise to several generations on the same 

 host in the course of each year, Dietel is unable to recognise 

 any sufficient cause for the disappearance of the aecidial generation, 

 and believes a more probable view to be that the ancestral form only 

 bore teleutospores, and that the uredo and aecidial generations 

 originated at a later phylogenetic stage, a hypothesis which receives 

 some support from Brefeld's well-known views regarding the origin of 

 the Uredines from the Auricularias, a saprophytic group which possesses 

 no spore form comparable with either aecidio- or uredo-spores, both of 

 which may have originated as an adaptation to a parasitic mode of 

 existence, though not necessarily on all the host plants inhabited by 

 the parent form. 



Ferments in Fimsri. 



^ j 



The fat-splitting ferment first obtained in a pure state by Professor 

 Green during his classical researches on the germination of castor oil 

 seeds, or at least a ferment possessing similar properties, has just been 

 obtained by Mr. E. H. Biffin {Annals of Botany, 1899, p. 363), from a 

 fungus which he was fortunate enough to find growing on the 

 endosperm of a germinating cocoa-nut, and which apparently belongs to 

 the Hypocreaceae, though to which section of the family it must 

 ultimately be referred remains undecided, owing to the constant sterility 

 of the perithecia, in which no ascospores have as yet been found, 

 though chlamydospores and sickle-like microconidia are abundant on 

 the mycelium. The fungus grows freely on sterilised slices of cocoa-nut 

 and Brazil-nut endosperm, as well as in cocoa-nut milk and similar media, 

 with the result that the oil which these contain gradually disappears, 

 being decomposed into glycerine and fatty acids, the former of which is 

 absorbed by the plant and forms its source of carbohydrate food 

 material, while the latter accumulates in the fluid and increases its 

 acidity. 



Mr. Biffin has succeeded in isolating the ferment by the usual 

 process of extraction with water and precipitation by means of alcohol, 

 when a white substance was obtained, which, when re-dissolved in 

 water, furnished a solution possessing the properties of the fungus, in so 

 far as these are concerned in the decomposition of fats. 



