388 ^'*<^ Fungi. [September, 



smut. Thus from a single fact he, like the former, jumps to a con- 

 clusion as to the cause and the remedy. It cannot be denied that 

 moisture aggravates greatly the disease from numerous facts collected 

 duriug a series of years. 



A fourth is a great man for insects. He believes fire-blight on 

 the pear, yellows in the peach, in short almost every disease that 

 vegetation is heir to, is produced by insects ; the tiredo-foetida or 

 smut, is nothing more nor less than the hatching and feeding of 

 numerous minute insects ; he is ready to bring distinguished names 

 in support of his fiivorite theory. A Mr. S. found upon some of 

 these diseased grains an insect, in form like a wood-louse, which he 

 said he knew from observation to be a species of acaris and these 

 Mr. S. considered the undoubted cause of this disease. But this 

 mere opinion, as it proves, has been refuted by searching observation 

 and may be disproved by the general fact that the acaris and aphides 

 and other minute insects feed more or less on all sorts of plants, 

 whether affected by smut or not, and almost always abound on 

 decaying vegetable matter or on plants which are diseased or in an 

 enfeebled condition. 



Still another alleges as the primary cause of the prevalence of 

 smut the numerous imperfect grains which have been sowed ; the 

 embryo being in some way impaired a malformation is effected and 

 a monstrosity is produced. But seed which is threshed and handled 

 in the same way is not always similarly affected. 



Another has no doubt that he has discovered the real cause, viz: 

 poverty in the soil. He has heard of chemical analysis and is 

 aware that certain ingredients are necessary for the full maturation 

 of the grain. But this cannot be true because one year he finds a 

 great deal of smut, while without manuring the nest year he reaps 

 a rich harvest. 



Another — and how many more we will not attempt to enumerate— 

 avers that it arises from fermentation occasioned from extra heat 

 and humidity from without. If this were so it would account for 

 its appearance only after the seeds begin to be formed, and if this 

 malady is thus produced the question may well be asked, when it 

 does occur why is it not more prevalent. 



Thus while this most pestiferous malady has been attributed to 

 organic weakness, wet seasons, fogs and hot sun, and to animalcule 

 and other contingencies, all of which may aggravate the symptoms 

 and accelerate the progress of the infection, it is due to science 



