336 



or pycnosijore. A spore arises as a swelling; at the tip of tlie stalk which 

 bears it and after it has reached a certain size, is cut off by a septum. 

 Spores vary in color, size,, and shape. When young they are hyaline, later 

 becoming greenish, and when mature are brownish. They may or may 

 not become septate; just what determines this is not understood. One- 

 celled spores in some cases develop two-celled spores in culture. The 

 sporophore is binucleate (Fig. 4) and as the swelling begins at the ter- 

 minal end, one nucleus passes into the swelling. About this time, a con- 



v'la- 5. PiuJtoiiiicro^r.ipii o/ a p.. .-.ii.lu.ii in m.-vKan sjjiio.n, dei'dop^'d (ui fruit of appl^' by 

 artifirial inoculation. Note the absence of an ostiole. 



striction begins to appear a sliort distance from the spore-end of the 

 stalk. This marks the line of di'taclunent of the spore from the sporo- 

 phore. i''urllier (levelo|iuienl caiiiiol be uiveii ;it pi-esciit. e\(t'i>t to say 

 that the mature spore is binucleate. 'I'lie most noteworthy difference in 

 size of si)ores is that they are larger on fruit and in culture than on 

 limbs or leaves. There is also sliu'-bt variatiou with host-plants. 



Sjiores readil.v LCeniiiiiale in water (I'M;:. V,), about six hours being 

 recpiired, tiiougli we have observed L,'eniiiiiat ion after ibree hours. The 

 tiil)e lii-st aiijiears as a slii;hl swelliui,' at one end or the side. Two-celled 



