98 



DROMYCES 



pari oi the world ; reported on raanj Leguminosae, but doubtless some of 

 these are distinct Bpecies. Jordi has distinguished under U. Fabae three 



Pig. 50. U. Fabae. 'IVleutospores 

 and uredospore on Vicia Cracca. 



Fig. 51. U. Fabae. Telento- 



spores and uredospore on 



Vicia sepivm. 



"biological" races— (1) on Faba vulgaris and Pi&um sativum, -1 on 

 Lathyrus vernus and probably also on Pisum sativum, (3) on Vicia Cracca, 

 Pimm sativum, and possibly also Vicia kirsuta. 



The secidial generation is frequent on some hosts, such as Vicia sepium 

 and species of Lathyrus. On Faba vulgaris and 

 Pisum sativum it is, on the contrary, very rare, 

 being recorded by Sydow, on the Pea, only from 

 Norway, East Indies and Japan 'Once from cadi . 

 It has been seen on the Bean in the East Indies, 1 >ut 

 seems to be not uncommon in artificial cultures, 

 in which Plowright produced it both on Pea and 

 Bean from the same teleutospores (Plowr. Ured. 

 p. 121). 



On the leaves of the common field Bean only 

 the uredospores are generally to be found, even as 

 late as mid-October, but on the stems the teleuto- 

 spores form large black sori. On Vicia sepium 

 the uredo-sori are often darker and covered by the 

 epidermis for a shorter time than on the Bean, 

 while the teleuto-sori occur in great abundance on the leaves and even 

 on the tendrils. 



If all the infected haulm, etc., were burnt instead of being put on the 

 manure heap or left to rot on the ground, the disease would become less 

 prevalent, especially if Jordi's idea is true, that the Bust on the wild 

 Vetches is a distinct biological race. In Ecuador, at Quito, which has a 

 very equable climate of "perpetual spring/' U. Fabae has, according to 

 Lagerheirn, become almost an isolated uredo. The same thing is true of 

 it in other tropical climes. 



Distribution : world-wide. 



Fig. 52. U. Fabae. 

 iEcidia on Tea, from 

 Plowright's culture, 

 in which he produced 

 them ou both Pea 

 and Bean from the 

 same teleutosport s. 



