Germination of Teleutospores of Ustilaginee. 75 
of De Bary, this germ-tube constitutes the promycelium. 
In the course of a few hours the promycelium has received 
into itself all the protoplasm originally contained in the 
spore, Transverse septa now make their appearance in it, 
and it thus becomes divided into four or five equal compart- 
ments. From the outer walls of the now septate promy- 
celial tube little offshoots or buds arise, into which the 
_ protoplasm of the tube passes (Plate VII. Fig. 1). These 
buds continue to increase in size until they become elon- 
gated, ovate, or elliptical promycelial spores; they then 
fall off. Generally they are produced from the side wall 
of the promycelium, near the septa, and almost always one 
is produced from the apex of this structure. If the proto- 
plasm in each segment be exhausted by the production of 
promycelial spores, then spore-formation from it ceases ; 
but if all the protoplasm be not used up in the formation 
of the first promycelial spore, a second but usually a smaller 
one is budded off. In fact, spore-development from the 
promycelium goes on until its protoplasmic contents are 
exhausted. It is not at all uncommon for one of these 
primary promycelial spores to remain attached to the pro- 
mycelium instead of falling off, and at its free end to give 
off a small bud, which gradually grows into a secondary 
promycelial spore, the latter being of smaller dimensions 
than the one from which it sprang (Plate VII. Fig. 2). These 
primary and secondary promycelial spores, after they have 
fallen away from the promycelium, show still further 
developmental changes in water. (1) They may, as Tulasne 
has figured, emit a germ-tube (Fig. 12)—a very narrow 
tube pointed at its extremity, into which the contents of 
the promycelial spore are passed.* (2) Two promycelial 
spores, being near one another, may become joined by a 
transverse branch, through which the contents of one of 
* Tulasne, ‘2° Mémoire,” pl. 12, figs. 22-24. 
