NOTES AND MEMORANDA. 333 



bined, different appearances arise. In some cases," continues 

 Mr. Berkeley, ''it produces an extreme degree of hardness, 

 inducing a condition like that of the mummified silkworms. 

 Sometimes, on the contrary, it causes rapid and loathsome 

 decay, especially when in company with the Peronospora." 

 Like the latter, it suddenly appears on the potato plant, carries 

 on its work of destruction, and vanishes. 



Till now I believe the resting condition of Fusisporium 

 Solanihcis never been described. In my attempt to work out 

 the history of Peronospora infestcms, the undoubted resting- 

 spores of the Fusiporium came to light in the following 

 manner : — A quantity of badly infected potato leaves were 

 selected and isolated last July with the view of watching the 

 Peronospora. As the presumed oospores of the latter gradually 

 appeared, there also appeared much smaller bodies, Avhich 

 also went to rest ; these were so similar in size and appear- 

 ance to antheridia or dead zoospores, that they were thought 

 to belong to one or the other. When I recently placed some 

 of the presumed oospores of Peronospora in pure water to 

 promote germination, all the smaller bodies at once burst, 

 and in the short space of six hours developed into perfect 

 plants of Fusispormm Solani. In size the spores measure 

 about the -o-j^o-f,- of an inch in diameter; they are palish brown 

 in colour, with a very finely muricated outer coat, and a light 

 central nucleus. The Fusisporium is frequently produced close 

 to the resting-spore, and I have observed the direct germina- 

 tion and production of the Fusisporium in innumerable in- 

 stances. How these resting-spores arose last year I am not 

 certain, but it is not improbable that they may be a different 

 condition of the aerial fruit broken up into four parts. 



Pythium Equiseti. — Mr. Worthington Smith writes in the 

 * Gardeners' Chronicle,' p. 656 : 



Great interest is just now attached to this curious parasite, 

 and hitherto it has not been recorded as British. Dr. Sade- 

 beck, of Berlin, described the plant last year as a new species 

 of Pythium, parasitic upon Equisetum arvense. It bears a 

 considerable resemblance to the bodies discovered last year, 

 and referred by me to the secondary condition of the Potato 

 fungus. It ultimately appeared that Dr. Sadebeck also last 

 year found a similar parasite infesting and destroying living 

 Potato plants near Coblenz, and at the time he referred the 

 Equisetum and Potato parasites to the same fungus, and on 

 seeing my micro-photographs he doubtfully threw out the 

 suggestion that all three fungi might possibly prove to be the 

 same with each other. 



