farmers' miscellany. 99 



3d. Salt instantly kills the worms, as any one may satisfy him- 

 self, with the assistance of the common compound microscope. 



Under the full impression of the existence of the fungus in the 

 potatoe, two questions present themselves. 



1st. Is the fungus the cause of the decay, or merely a growth 

 on the tuber already diseased from some other cause ? — and 



2d. When and in what part of the plant the disease originates, 

 and how it is propagated and disseminated ? 



The probability is that the fungus is the cause of the disease — 

 for the fungus appears on the skin of the potatoe, and can be tra- 

 ced by its gradually dark color penetrating from the outside by 

 degrees into the sound inside, the outside fungus developing itself 

 first, and producing slime and rottenness, while the inside yet re- 

 mains hrm and sound. If the fungus resulted from the potatoe 

 first becoming rotten, and thus forming favorable circumstances for 

 its vegetation, then the presumption is that we should occasionally, 

 although perhaps rarely, find parts of the potatoe rotten without 

 the fungus, which I, at least, have never yet seen. I have often 

 seen heaps of rotten potatoes, without ever before observing this 

 peculiar fungus, which, on account of its smell, cannot be mistaken. 

 If this was therefore a disease merely affecting the rotten potatoe 

 and not the sound one, it would have been long ago and much 

 more often observed. Dr. Wallroth, an excellent German botanist, 

 who appears to have closely studied the fungus family, observes in 

 the Linnea^ (a botanical periodical, published in Germany,) Vol. 

 XVI. for 1842, that he has ascertained the disease called there the 

 potatoe scab, or loar^ — a kind of swelling or tumor, ending in rot- 

 tenness — to be a species of subterranean fungus, which he calls 

 Erysihe subterranea, and of which he gives a long scientific de- 

 scription. I am not sufficiently versed in this subject, to decide 

 whether this description agrees exactly with the disease at present 

 under discussion, but it appears to me to differ in several partic- 

 ulars. 



The second question, as to the origin and propagation of this 

 fungus, is one which presents great difficulties in its solution. 

 These arise partly from the knowledge of the propagation of the 

 fungus family being yet in its infancy, and partly from the want of 

 means of pursuing the study of this microscopic subject properly. 

 From the almost universal accounts of the tops of the plants hav- 



