83 British Uredinee and Ustilaginee. 
however short it may be, there is always one septum 
developed near its upper end. The tubercles above men- 
tioned increase rapidly in length, and become the primary 
spores (Plate VI. Fig. 7). They are filiform bodies, curved 
in various ways, and measure from 80 to 100 in length ; in 
number they vary from four to twelve or more, according 
to the size of the spores from which they are developed. 
When all the protoplasm from the promycelium has been 
absorbed into these primary 
spores, they become cut off from 
it by septa at their attached 
ends. If the promycelium be 
so situated that it cannot reach 
the air, no primary spores are 
produced. Shortly after their 
maturity these primary spores 
conjugate (Plate VI. Fig. 8), or 
become united by transverse 
bridges, usually in pairs. The 
primary spore is possibly a 
Fig. 7.—Germinating teleutospore of 
Tilletia tritici, producing a cluster of wind-carried spore, but, as in 
primary promycelial spores, A conjugated 
pair of promycelial spores producing two artificial cultures they are not 
secondary spores—an unusual circumstance é 
(ss). A secondary promycelial spore which E€Xposed to this force, they fre- 
has produced a tertiary (s#). (Tulasne.) , fe ‘ 3 
quently germinate zz sztu. This 
they do by a repetition of the oft-described process of 
protoplasmic migration, with septation of the emptied 
parts ; the protrusion of a bud-like process into which the 
protoplasm is emptied, and which becomes a secondary 
spore. The end of the promycelium, after the primary 
spores’ have fallen off, remains tuberculated, showing the 
points of their attachment. The conjugation of two 
primary spores cannot be considered a sexual act, in- 
asmuch as the single spores, which have not been sub- 
jected to it in any way, germinate as freely, and produce 
