254 INTRODUCTION TO THE STUDY OF FUNGI 



The surface of the epispore varies in its character, being some- 

 times quite smooth, in other species reticulated, in others so 

 minutely granular as to appear to be smooth until closely 

 examined, or in others distinctly rough and either obtusely 

 warted or spinulose. In colour they seem to be black in a 

 mass, but viewed obliquely sometimes with a yellowish or 

 olive tinge ; seen under the microscope, by transmitted light 

 they may be black or brown, violet, olive, or yellowish, and 

 rarely hyaline. Where colour is present it resides in the 

 epispore, and is fairly constant in each species when mature. 



The form is commonly globose, or approximately so, when 

 perfectly free, but being usually closely compressed in growth, 

 is apparently angular. The spore -masses in some genera, 

 such as Ustilago and Tilletia, are more loosely packed, and the 

 teleutospores do not adhere to each other in definite clusters, 

 but are normally free. In Sorosporium and Thecaphora they 

 form compact clusters, which in the latter genus separate with 

 difficulty, whilst in Cintractia, although at first agglomerated, 

 they soon separate. In Urocystis there are a few large, dark- 

 coloured fertile spores, closely adnate to each other in the 

 centre, and these are surrounded by hyaline sterile cells, or 

 pseudospores, which give the appearance of a beaded border. 

 In JEntyloma, Melanotaenium, and JEntorrhiza we meet with 

 aberrant genera, which remind us of Protomyces and Synchy- 

 trium, and are probably more closely allied to the latter than 

 they are to the rest of the Phycomycetes. 



Germination of the teleutospores in this family has often 

 been observed and watched. In some species a small germ- 

 pore has been observed, but they are never so distinct as in 

 the Uredineae. When the spores germinate they protrude a 

 germ-tube — usually designated, for reasons hereafter evident, 

 a promycelium. In a certain sense it may be regarded as 

 analogous to the protonema of mosses. This promycelium 

 bears small hyaline bodies, which resemble spores, and are called 

 by Continental mycologists sporidia, a name to which we take 

 exception as it should be restricted to spores generated in asci. 

 We will, call them, for the time, promycelial spores, as suggested 

 by Plowright, and much more appropriate. The promycelial 

 spores will bud and produce secondary promycelial spores, 



