272 BOTANICAL GAZETTE. 



the spores A perusal of the admirable paper of Woronin, Bei- 

 trag zur Kenntniss der Ustilagineen, shows how large a part the 

 germination plays in the limitation of the genera, and when one 

 bears in mind how little is known of the germination of our na- 

 tive species, he will understand how imperfect the classification 

 of our Ustilagine<r must be. In the present article I would like 

 to call attention to some of our little known forms, without pre- 

 tending to regard my determination of the species as anything 

 more than provisional, expecting that increased knowledge of the 

 development, which it is to be hoped we shall soon have, will 

 necessitate a reform in the nomenclature. 



The genus Entyloma, founded by DeBary on Protomyces micro- 

 sporus, Unger, includes a comparatively small number of species, 

 in which the small mycelium inhabits the leaves of different her- 

 baceous plants, and where the spores are formed in the contin- 

 uity of the hyphre, usually in large numbers, but do not become 

 pulverulent as in most Ustilaginece. The germination of the spores 

 resembles that known in species of Tilletia ; a short germinal 

 tube is given off, at whose apex is borne a whorl of short cejls 

 which unite with one another in pairs. In some of the species 

 of Entyloma, besides the spores in the interior of the leaves, there 

 are conidia borne on stalks which penetrate the stomata in dense 

 tufts and form white pulverulent spots on the leaves. Schroeter 

 makes two divisions of the genus according as the species bear 

 conidia or not. The spores of the greater number of species of 

 this genus are very nearly alike in size and shape, being oval or 

 somewhat angular, and in most cases it is not easy to define the 

 species by the spores alone. The presence or absence of conidia, 

 it seems to me, can hardly be regarded as constant in all cases, 

 for, as in the form on Ambrosia, the conidia are sometimes pres- 

 ent, but more frequently they are wanting. The conidia are 

 usually like the forms referred to the genera Fusidium, Cylin- 

 drospora or Ramularia and, in the case of our species, it may be 

 that the conidial forms have already been described as species of 

 the genera above named, without reference to the spores in the 

 interior of the leaves ; but if such is the case I have been unable 

 to trace them. 



The type of the genus belonging to the division in which there 

 are no conidia is Ent. miorosporum (Unger), DeBary, which has 

 been found by Prof. Arthur on Ranunculus repens near Chicago, 

 but, although I have often searched for it, I have never found it 

 near Cambridge. Another species found on Ranunculus in Eu- 

 rope, which has no conidia, Ent. Ranunculi (Bon.), I have never 



