THE FUNGI WHICH CAUSE PLAMT DISEASE 615 



Dendryphium Wallroth (p. 609) 



Hyphae creeping or obsolete; conidiophores erect, with short 

 apical branches; conidia cylindric, 2 to many-septate, catenulate, 

 brown. 



Some thirty or more species. 



D. comosum Wal. is the cause of a cucumber leaf spot in England. 



Dematiacese-Dictyosporse (p. 594) 

 Conidia dark, rarely light, muriform, globose to oblong. 



Key to Genera, of Dematiaces-Dictyosporse. 



Hyphse very short or scarcely different from 



the conidia I. MicronemeaB. 



Conidia not in chains 

 Conidia not appendaged 

 Conidia irregidarly muriform or 

 sarciniform 

 Conidia with a conic point at each 



side 1. Oncopodium. 



Conidia without conic points 

 Conidia globose to oblong 

 Conidia ovoid to oblong, loose 2. Sporodesmium.p. 616. 

 Conidia globose to ovoid, ag- 

 gregated 3. Stigmella. 



Conidia sarcinseform, often co- 



alescent 4. Coniothecium, p. 617. 



Conidia as if copiposed of parallel 

 chains of cells 

 Chains of conidia never separat- 

 ing 5. Dictyosporium. 



Chains of conidia separating 6. Speira. 



Conidia comiculate at agex 7. Tetraploa. 



Conidia in chains, often asperate or with 



isthmi 8. Sirodesmium. 



HyphsB distinctly different from the conidia II. Macronemese. 

 Conidia of the same form 

 Conidia not in chains or capitate 

 Conidia bearing little conidia on their 



surfaces 9- Xenosporium. 



