198 ON THE PERONOSPOKiE. 



acrospores minute, sub-globose ; apices with broad, depressed 

 papillae, produced in the spicular processes. Oospores small, 

 globose, and of a yellowish tawny colour. I quote the fol- 

 lowing from Mr. Worthington Smith, in the Gardener's Chroni- 

 cle for Nov., 1883 : — " As too often happens with names of fungi, 

 various botanists have, with insufficient reason, altered the name 

 of the Lettuce fungus. Corda was the first to do this, and he 

 changed Botrytis to Fero?tospora, and since then the fungus has 

 been generally known as F. ga?iglto?iiformts. De Bary did not 

 approve of ' ganglioniformis,' so altered it to * gangliformis.' Then 

 Tulasne re-named the fungus P. parasitica, var. lastiiccB. And 

 lastly we observe that Dr. Max Cornu prefers P. gangliiformis.^^ 

 We have recently seen it suggested that a society should be formed 

 for the purpose of taking back Cleopatra's Needle and other 

 Egyptian and Grecian antiquities now in Europe, to Egypt and 

 Greece. Perhaps the time may some day arrive when a society 

 will be formed for the reconstitution of old generic names and the 

 obliteration of many worthless new ones. Botrytis is a far better 

 name than Peronospora, for the former means a bunch of grapes, 

 and refers to the appearance of the fungi as they hang down from 

 the under-surface of leaves very much in the style of bunches of 

 grapes. Ganglioniformis refers to the fruiting-threads of the 

 fungus, resembling the natural enlaigements, termed ganglions, in 

 the course of a nerve. Berkeley pointed out in the first volume 

 of the Journal of the Royal Horticultural Society, in 1846, that 

 lettuces were at that time subject to a putrefactive disease, caused 

 by a fungus closely allied to the fungus of the potato disease, and 

 named by him Bot. ganglioniformis. He described the fungus as 

 common in the spring ; but it appears that there are two crops of 

 this fungus every year, and that the most virulent is generally in 

 September or October. The invasion of lettuces in the late 

 autumn is often so destructive that it entirely destroys the harvest 

 of lettuce seeds. 



The ganglion-like swellings of the branches are a pecuHar fea- 

 ture of this fungus. The end of each fine ultimate branch is most 

 beautifully dilated into a saucer-like expansion, with a single exces- 

 sively-attenuated spicule growing from the centre of each saucer, 

 and from three to five spicules round its margin. Each spicule is 



