THE ONION-SMUT. 171 



The most probable supposition is that the onion-smut came 

 originally from some of our wild species of onion ; for although 

 it has never yet been found on any wild species, it must be 

 borne in mind that the fungi of this country have as yet been 

 but very imperfectly explored. The species of Urocystis 

 most nearly related to U. Cepulce, is, perhaps, U. Colchici of 

 Europe. We cannot find any record of the Golchicum having 

 been introduced into this country, and it is, therefore, futile 

 to discuss the question of the connection between U. Cepulce 

 and U. Colchici. Recently,* Mr. Worthington G. Smith has 

 described a new species of Urocystis, which produces a disease 

 of gladiolus bulbs. Judging from his figure, however, it 

 would seem to differ essentially from U. Cepulce in having a 

 number of spores packed together in one mass, whereas the 

 onion-smut has generally only one, or, at the most, two spores 

 united together. 



Having thus passed in review the history of the disease, 

 and examined the fungus which causes it, let us consider the 

 application of the facts already enumerated to the method of 

 checking the disease. We have seen from the character of the 

 fungus, that we are not to expect to find any secondary, or 

 hibernating, stage of the fungus in any plant growing with or 

 near the onion crop. On the contrary, the complete growth 

 and development of the fungus is in the onion-plant itself, or 

 possibly also in some of the wild species of onion, although 

 the last has not been proved. It is evidently a wise pre- 

 caution to destroy wild onions when growing near cultivated 

 fields. As a matter of fact, the wild onions of New England 

 are not sufficiently abundant to be much feared ; but farther 

 South, in Southern Pennsylvania and Virginia, they prove 

 very common and troublesome weeds. It seems to have been 

 considered a fact by the farmers of the Southern Middle 

 States, that onions cannot be as easily cultivated with them 

 as farther East. It would be interesting to know whether 

 there is any connection between the greater difficulty ex- 

 perienced in raising onions in the South, and the greater 

 abundance of wild onions. If the smut came originally from 

 the wild onion, we should expect such to be the case. 



* Vide Gardener's Chronicle, 1876, p. 420-22, and Monthly Microscopic Journal, 

 December, 1876, p. 304. 



