184 FETCH : 



the formation of the stroma in Aschersonia Aleyrodis as 

 follows : — 



"The fungus does not spread over the leaf to any extent, 

 but grows upward in a mass, gradually spreading over the 

 larval scale. It is not uncommon to find the peritliecia (i.e., 

 pycnidia), with their bright coral-red masses of sporules 

 formed in a circle round the edge of the larva while it is yet 

 visible. As the Aschersonia develops, the hypha) spread over 

 the larva, forming a dense, compact stroma, which ultimately 

 entirely envelops the lar\a. The stroma in this stage is thin 

 and disc-like, the fructification being usually borne in a circle 

 near the edge. The hymenium at tliis time is spread out on 

 the sarface of the stroma, or but slightly sunken, the sporules 

 projecting in a conical coral-red or rufous mass. As the 

 fungus develops, the stroma becomes thickened and hemis- 

 pherical, and the hymenium gradually becomes immersed." 



The interpretation is doubtless correct if we accept the view 

 that the thin and thick stromata represent stages of develop- 

 ment, i.e., that the thicker stromata were produced by the 

 continued growth of thinner stromata which were aheady 

 bearing conidia. Bat that is not necessarily the case. In all 

 probability the thick and thin stromata on a given leaf are 

 all the product of the same infection, and consequently all 

 of the same age, their different thicknesses being due to a 

 difference in vigour of growth. The occurrence of stromata 

 in which the pycnospores are immature, and the pycnidia 

 nearly closed, would appear to show that the pycnidia in the 

 thicker examples are produced within the stroma and subse- 

 quently open widely. In pulvinate forms of Aschersonia 

 placenta the pycnidia are often oval with a narrow orifice. 

 That the cavity of the pycnidium originates as an invagination 

 of the surface of the stroma is not excluded. 



The pj'cnidia are lined with short, densely crowded basidia. 

 As far as my observations go, the basidia are simple, but 

 Miyabe and Sawada have shown that branched bapidia may 

 occur in Aschersonia Coffess, A. Tamurai, and A. marginata. 

 The pycnospores are produced singly at the apex of the 

 basidium, and as the pycnidia are, when mature, completely 

 filled with spores, while in some cases a dense mass of extruded 



