TAB. CCCCXI. 



UREDO PoRRi. 



X HIS pretty parasite was found on the waste part of the 

 leaf of a leek, toward the base, and was most conspicuous 

 within the leaf. It is not uncommon, and I believe does not 

 much hurt the growing plant. It seems to burst from under 

 the cuticle like other Uredos, and is composed of a number 

 of round, nearly transparent, light green stiped capsules, 

 each about lOOOdth of an inch in diameter, containing 

 apparently bright orange seeds. 



It is somewhat remarkable that this kind of parasite grows 

 on living plants, whereas the Sphaeriae and many others are 

 more usually found on decaying or dead vegetables. I pre- 

 sume a little marked attention will point out the way to 

 avoid these evils, Avhich, if such attention be omitted, may 

 occasionally aggregate into a serious evil. We ought to 

 thank Sir Joseph Banks for his account of the Blight in Corn, 

 Uredo Frumenti, tab. 140. ; and his highly magnified 

 figures. It is a very laudable undertaking for men of for- 

 tune to support the more expensive elucidations in Natural 

 History. 



We have no doubt of seeds floating in the air, notwith- 

 standing Dc Candollc's* argument. See Description and 

 Tab. 136 and tab. 318. Ilehclla mcmbranacea, which is 

 attached to living mosses and grasses by a thin film. 



* Do.Candolle sur les champignons parasites. Annalcs du Mosoum d'Histoire 

 Natuiflle, tome neuvifme, 1807. 



