446 PETCH : 



are^-" Perithecia collected in a stroma, clothed with brown 

 mycelium ; basidia and sporules with paraphyses intermingled ; 

 otherwise as in Diplodia." 



Since then other subgenera have been instituted, viz. : — 

 Microdiflodia, with distinct pycnidia, and spores less than 

 15 ^ long ; Pellionella, with subsuperficial pycnidia produced 

 into a beak, ''Est Diplodiella rostrata" ; Rhynchodi'plodia, 

 which is a beaked Chcetodiplodia ; and Diplodiopsis , wliich is 

 a superficial, granulato-rugulose Botryodiplodia. With these 

 last four this communication is not concerned, except that in 

 so far as they are based on the older scheme of subdivision 

 they are open to the same objections. 



How this subdivision works in practice is best illustrated by 

 the following example : — 



In 1892, PatouiUard (1) described Botryodiplodia theohromce ^ 

 on fruits of cacao from Ecuador. Its pycnidia are 200 ^ 

 diameter, more or less villous, united in a black villous stroma ; 

 the spores are brown, uniseptate, 25-35 X 12-15 ja ; basidia 

 hyahne, 50 ^ long. A note in Saccardo adds "ad Ghceto- 

 diplodiam vergit," but this does not appear in the original 

 description. 



In 1894, Prillieux and Delacroix (2) described Macrophoma 

 vestita on the roots of cacao from Central America. Its pycnidia 

 are 300 [x diameter, with hyaline, non-septate spores, 30 X 15 jJi-. 

 The pycnidia are figured as simple and isolated. 



In 1897, P. Hennings (3) described Diplodia cacaoicola 

 on branches of Theohroma cacao from the Cameroons. Its 

 pycnidia are scattered, immersed in the cortex ; and its spores 

 are 22-28 u. x 12-14 p.. This species was investigated by 

 Howard in the West Indies, and from his account (5) we are 

 able to add more details to Hennings' brief description. 



Howard states that the rind of sugar cane is ruptured by the 

 growth of dark bodies underneath, which are arranged in 

 more or less vertical lines. These are colonies of true pycnidia . 

 formed just beneath the rind, in connection with a dark- 

 brown, septate, branched mycelium abundant in the tissues 

 of the plant. His figure 11, which illustrates the growth of 

 the fungus on cacao, shows four adjacent erumpent pycnidia 

 in a basal weft of hyphae. The pycnidia are said to contain 



