in Vegetables by Fungi. 87 



tiu'nep^ radish, parsnep, carroty cucumber, and other cucurbita- 

 ceous plants. 



The productions most hable to this fungoid disease would 

 appear to be the more succulent kinds, and this fact accounts for 

 the greater frequency of the disease in damp seasons. 



Cheshunt, June 9th, 1843. 



Note, July 17th. — The same evening on which I noticed the 

 disease in the lettuce, I introduced the filaments of the fungi into 

 numerous unafi'ected lettuces in different stages of growth and 

 widely separated from each other, and in a few days I had the 

 satisfaction, which I anticipated, of beholding the complete and 

 perfect success of the experiment, and finally, the destruction of 

 all the plants inoculated. 



Encouraged by the marked success which attended the inocu- 

 lation of the lettuces, I determined to treat in a similar manner 

 vegetables of difibrent kinds, feeling however considerable doubt 

 as to the issue of this new experiment. I therefore inoculated 

 the stems and seed-vessels of beans and peas, the stem and tuber 

 of the potatoe, the top root of the tm-nep, leaves of rhubarb, and 

 stem and leaves of the cabbage. At the same time I inoculated 

 also the but little developed fruit of the apple, peach and goose- 

 berry. Now a result no less satisfactory than in the previous 

 case followed the inoculation of the productions above enume- 

 rated, differing from each other too as many of these do so widely 

 in textm'e and affinities, the progress of the ravages of the fungi 

 being however greatly modified by the condition as to density of 

 the vegetable, or portion of the vegetable operated upon. Thus, 

 their devastating progi-ess in the tuber of the potatoe, in the top 

 root of the turnep, and in the seed-vessel of the bean was very 

 rapid, as might have been expected, since these consist almost 

 entu'ely of loose cellular tissue and fluid which could offer but little 

 resistance to the extension of the fungi ; while in the stems of the 

 potatoe, bean and pea, the progress was much slower, owing solely 

 to the greater density of the parts. 



The singular fact of the rapid development of fungi when in- 

 troduced into the living vegetable oeconomy, materially afiijcts the 

 views generally entertained as to the office and power of fungi in 

 creation. 



One of the greatest peculiarities of the fungi consists in the 

 preference which they manifest for organic matter in a concen- 

 trated form. But it has hitherto been supposed that their pow- 

 ers were confined to dead organic matter* which they speedily de- 



* This statement is by no means correct ; the researches of Ehreuberg, 

 Meyen, and many other physiologists have long since proved the falsity of 

 this now antiquated notion. The inoculation of sound fruit with fungi was 

 made so far back as 1819 by Prof. Ehrenberg. See his memoir ' De My- 

 cetogenesi epistola,' Nova Act. Nat. Cur. vol. x. — Ed. 



