26 British Uredinee and Ustilaginea. 
follows that if all the spores in the field present this 
central germ-pore, then of course there must be a corre- 
sponding pore on the opposite side (Plate II. Figs. 4-7 
and 10), so that when germination commences, the spores 
assume a rounded cuboid form, with a germ-pore at each 
angle. The process of germination continues from one 
of these germ-pores, rarely from more than one. The 
outgrowth of the endospore progresses, until it assumes 
the form of a blunt-pointed, cylindrical tube. Into this 
tube the protoplasm of the spore passes, and with it the 
otange granules which give the colour to the spore. The 
tube grows onwards for a considerable distance—-ten or 
more times the diameter of the spore. Contemporaneously 
with the growth of the germ-tube, the protoplasmic con- 
tents are continuously passed onwards to its extremity ; 
so that the longer the germ-tube grows, the further are 
the orange granules removed from the spore in which 
they were originally. contained (Plate II. Figs. 6, 7, 10, and 
14). The further development of the germ-tube consists in 
its continued growth ; the walls, however, become not only 
distinctly thinner, but give off various branches, mostly at 
a right angle to the axis of its growth (Plate II. Fig. 7). 
While these changes have been taking place, the whole 
germ-tube has been making a series of convolutions, some- 
_times from right to left, sometimes from left to right 
(Plate II. Fig. 6). Often a germ-tube will turn in one 
direction during the first part of its course, and in the 
opposite during the latter part. These circumnutatory 
movements were observed by Tulasne* in 4c. crassum, 
viole, etc. This circumnutation of the germ-tubes I have 
only observed in the Uredinee, and it is quite distinct from 
the torsion one observes in other mycelial hyphe, when they 
extend themselves into a dry atmosphere.. This has been 
* Tulasne, ‘2° Mémoire,” p. 128, 
