On Smut in JVheaU 25 



mentioned as being destroyed the first season were the 

 white wheat, and the red-chafF bearded wheat; both were 

 injured, though the white much more than the beard- 

 ed wheat : since that time J have sown the bearded only. 

 I would further observe, that the origin or cause of 

 smut in grain has not, as yet, been well ascertained. The 

 opinion most generally accepted is, that the seed before 

 being sown, is impregnated with the Qg^ of some insect, 

 or contains the insect itself, which insect preys upon the 

 standing grain the succeeding season, and occasions the 

 disease alluded to, and the effect of the acid in prevent- 

 ing it, seems to favour this opinion ; but the following 

 facts are in opposition to this theory. Suspecting that the 

 ear or grains ot the diseased wheat were affected, and not 

 the root stalk, or blades; I enclosed, soon after harvest, a 

 head in a large phial, properly secured with paper perfo- 

 rated in several places with a pin, to admit fresh air. 

 Nothing appeared till about the beginning of the present 

 month, when I found an insect of the fly or rather bug 

 kind, which appeared to have lately left the grain, the 

 chaff being perforated, and the black dust from the grain 

 fallen through it to the bottom of the glass ; since that, 

 several others have made their appearance. This insect 

 resembles, in some degree, the common rose bug, ex- 

 cept that it is more arching on the back, is black, and is 

 much less, not being more than the sixth or eighth part of 

 the size of the rose bug. They are active, and fly from one 

 part of the wheat head to another. From this discovery it 

 "would appear, that the smut grains were the mere nests 

 or places of deposit for the eggs of an insect of the kind 

 above described, with which it had been impregnated 

 vhile in its soft or milky state, and which I have no 

 doubt is the true cause of the disease. Admitting this 

 to be the case, it is not easy to account for the remedy or 

 prevention thereof from the application of the sulphuric 



