59i 
Gnomonia erythrostoma , Pers. 
the cytological characteristics of male cells—viz. a relatively large nucleus, 
a small amount of cytoplasm, and absence of food-reserves. The cyto¬ 
logical features of the spermatia of Gnomonia are identical with these. 
One can also point to the striking similarity in general structure between 
the spermogonia of Gnomonia and those of the Uredineae. The fact that 
no success has attended one’s efforts to induce the spermatia of Gnomonia 
to germinate is in keeping with the inability exhibited by the spermatia of 
the Uredineae to undergo further development under all conditions approxi¬ 
mately normal. 
In this connexion it is interesting to compare the cytological characters 
of the pycnidiospores of a species of Phyllosticta frequently found associated 
with Gnomonia on old Cherry leaves. Phyllosticta is a genus belonging to 
the Sphaeropsidales. The pycnidiospores of this genus readily germinate. 
Fig. 6 a shows some of stained spores of the species of Phyllosticta found on 
old Cherry leaves. It will be observed that the relation between the size of 
the nucleus and the amount of cytoplasm is radically different from that 
holding in the spermatium of Gnomonia. 
The fact that in Gnomonia some spermogonia are always produced 
before the formation of the coiled structures (to be described later) is what 
one would expect if the spermatia at present or in the course of recent 
phylogeny performed a fertilizing function. In the Rusts, too, one finds 
that the formation of spermogonia precedes that of aecidia. 
Some authorities, e. g. Brefeld ( 4 ) and Christman ( 5 ), hold that the 
spermatia of the Uredineae are simply asexual spores which have lost the 
power to germinate; but their cytological characteristics, as first demon¬ 
strated by Blackman, seem to negative this view. 
Trichogynes and Ascogonia. 
Soon after the beginning of the formation of spermogonia, groups 
of hyphae towards the lower epidermis begin to entwine themselves closely 
together and so form the ‘ coils ’ (i. e. the ‘ Knauel verflochtener Faden ’ 
of Frank) which are the earliest stages of perithecial development (Fig. 8). 
The hyphae which become compacted into these ‘coils’ cannot be distin¬ 
guished from vegetative hyphae. The c coils ’ are roughly spherical in 
shape, but they differ much in size, their diameter varying from 40 ju-100/x. 
It is generally found that certain hyphae connected with the periphery of the 
‘ coils ’ pass out through a stoma. These hyphae, the trichogynes of 
Frank ( 17 ), are most often grouped together in a compact bundle of two to 
five which protrudes slightly from the stoma. The trichogynes passing 
through any one stoma are closely compacted together in the apical region 
(Figs. 7, 8). The group becomes somewhat narrowed while passing through 
the stoma, but when clear of it expands again and terminates as a dome¬ 
shaped mass (Fig. 7). The cell walls at the tips of the trichogynes become 
