IBT G. P. DARNELL-SMITH. 877 



discharge of spores from tins pycnidiuni. Such a pycniflium is 

 shown in PI. Ixxxvii., Hg.l3. A noticeable feature of theliyphtv 

 is the ease with which they anastomose. Anastomosis may occur 

 in two ways. A branch from one hypha may grow out and fuse 

 with another lying parallel or nearly parallel to the one from 

 which the branch originated, or branches may arise from two 

 adjacent hyphjf, approach each other, meet, and fuse. Examples 

 of this are seen in PI. Ixxxvii., fig. 13. The pycnidium hero 

 figured took a little over three weeks to form, and ultimately 

 discharged "x" spores only. In other hanging drop cultures, 

 where noimal pycnospores have been discharged, they have never 

 been observed to germinate, without transference to a fresh 

 medium, the mycelium having apparently exhausted the medium 

 upon which it was growing before the production of pycnidia. 



Development of the Pycnidia. 



By means of cultures in hanging drops, and serial sections of 

 cultures upon agar, it has been possible to follow tlie develop- 

 ment of the pycnidia in detail. 



The beginning of pycnidia-formation consists in one or more 

 adjacent h37phaj producing lobulated branches of much greater 

 diameter than the ordinary hyphie (PI. Ixxxvii., figs. 14, 15). 

 These lobulated branches stain rather more deeply with hsema- 

 loxylin than the ordinary hyphjfi. 'J'he lobulated branches become 

 greater in number and interwoven, and many septa develop (PI. 

 Ixxxviii., figs. 16, 17). This leads to the formation of a firm, com- 

 pacted pseudoparenchyma; the protoplasm which lines the cell- 

 walls contains numerous deeply-staining particles, and becomes 

 especially distinct (PI. Ixxxviii., fig. 18). 



Soon, the parenchymatous body ig distinguishable int(j outer 

 layers of small, thick-walled, brownish cells: and an inner region 

 of larger, thin-walled, parenchymatous cells. In the inner region, 

 we, later, find groups of hypha3 with thin lumina, and, in their 

 place, arise, at a later date, the loculi of the pycnidia. 



In the transition-stage from parenchyma to hyphte, the walls 

 of the parenchyma cells frequently appear to be dissolved, and a 

 mass of naked protoplasm, with deeply staining granules, is seen 

 (PL Ixxxix., fig.l9). 



