On L^fnuf in IFheat. ' 81 



But this, being at present, a matter of conjecture only, 

 is submitted to the future observation of the inquisitive 

 naturalist, possessed of a penetrating eye, and powerful 

 microscope. 



If the preceding new doctrine be true, it will tend to 

 correct some received opinions, and prove that many of 

 the diseases termed blights, hitherto attributed to othet 

 causes, wdll, on a more close inspection, be found to ori- 

 ginate from a parasitical vegetation, or the depredation 

 of insects; either of which causes may probably operate^ 

 by depriving the grain of its nutritious sap* 



POSTSCRIPT, 



In a late elaborate essay, which we have just had 

 the pleasure of perusing, the author Mr. Robert So- 

 merville endeavours to prove, that the smut originates 

 from a very minute insect, which he detected in the 

 smut ball by the microscope, but not till it was put in 

 motion by the heat of a candle.^ That it appeared red, 

 and resembled a boiled lobster, and afterwards turned 

 black and was covered with a crustaceous coat, in which 

 state it remained till it died. — That the dark coloured 

 stains, on the stems of wheat are produced by its excre« 

 Tnent. That it wounds the tender stem, at the place of 

 the insertion of the grain ; preys on the milky juice, and 

 deprives the ear of nourishment. That the smut balls 

 consist of fine vegetable earth, which the diseased plant 



^ Communications to the Board of Agriculture. Vol. 2. p. 214, 



y 



