THE JOURNAL OF MICROSCOPY 



AND 



NATURAL SCIENCE: 



the journal of 

 The Postal Microscopical Society. 



OCTOBER, 1884. 



®n tbe peronoepor^. 



By George Norman, M.R.C.S.E. 



Plates 20, 21, 22, 23, 24. 



Second Part. 



AVING given a general account of the life-history 

 of the Peronosporoe, we can now proceed to examine 

 some of the more striking members of the genus, 

 beginning with those least known, and reserving the 

 potato fungus to the last. 



P. Gangliformis, the Lettuce Peronospora. 



Threads of the mycelium stout, now and then 

 torulose; suckers vesicular, obovate, orclavate; fertile 

 threads, 2 — 6 times dichotomous, sometimes tri- 

 stems and primary branches slender, dilated or 

 inflated above; the ultimate ramuli inflated at the apex into 

 a turbinate or sub-globose vesicle, bearing from 2 — 8 spicules ; 



p 





chotomous ; 



