CUCURBITARIA. 



•209 



unicellular couidia, at first white, later grey. It is these pycnidia 

 which cause the line perforations of the periderm of twigs. 



Yet another form of pycnidia, previously known as Diplodia 

 ojtisi (Awd.), (No. 4). This, like the last, breaks through the 

 corky layers of the bark. It has a peridium composed of loose 

 pseudoparenchyma and, without the intervention of conidio- 

 phores, produces two- celled conidia of a dark greyish-brown 



Fig. \QQ.—Cucvvhilaria laburni. Perithecium isolated. A, Ejaculating asciis 

 with the inner membrane as yet unruptured, but emerging beyond the outer 

 ruptured coat. (After v. Tubeuf.) 



colour. This form, however, I failed to finil in the course 

 my investigation, although I looked through much material. 

 Tabulating these various forms of fructification we have : 



of 



A. Pycxidia. 

 . White transparent, small, unicellular conidia on lontr conidiopliore.s : 

 {a) Free on the stroma. 

 (6) Enclosed in cavities in the stroma : 



(a) In cavities as yet not resembling pvcnidia. 

 (/3) In cavities with firm dark-coloured periphery. 

 (o) Enclosed in dark-coloured free pycnidia, with a peridium of coarse 

 pseudoparenchyma. 

 . Brown, unicellular, round conidia, in little brown pvcnidia (Fig. f>!), a). 



