Ecidiospores. 25 
tion, by Mr. W. G. Smith, was taken from the living plant, 
and is therefore reliable, although my own impression was 
that the elongation of the pseudoperidia was not quite so 
pronounced. In some species the cells of the peridia 
naturally adhere more firmly, as in 4c. ornamentale, Pert- 
dermium, Restelia, In Atcidium pini the peridium opens 
at the apex, but the margin shows very little tendency to 
become recurved. In R. cancellata the peridia do not open 
at the apex. This remains entire for a long time, and 
surmounts the peridium as a conical cap. The peridial 
cell-series, however, below this separate from one another 
laterally, so that the spores escape through a number of 
longitudinal fissures—a sort of lattice-work. 
The membrane of the zcidiospore is not of uniform 
strength, inasmuch as at certain points, when the spore 
germinates, there are pushed through it prolongations or 
outgrowths of the endospore. These potential openings 
(germ-pores) are exceedingly difficult to observe in the 
mature spore. When, however, the spore begins to. ger- 
minate, they become obvious. De Bary* gives the 
number of germ-pores in 4c. tragopogonis as three, and 
those of 4c. asperifoliit as four, From my own observa- 
tions, I should say the zcidiospores of Puccinia graminis 
and poarum have six germ-pores. When these spores 
begin to germinate they become somewhat quadrangular, 
with a germ-pore at each angle; but in addition to these 
a central opening or thin place appears in the centre of 
that side of the spore which is uppermost, and as, of 
course, both the upper and under sides of a spore cannot 
be seen in the same preparation at the same time, it 
* De Bary, ‘‘Champ. parasit,” Am, des Sct. Nat., 4° sér. tome xx., 
Reprint, p. 76, t. ii. fig. 7. 
+ De Bary, ‘‘Neue Untersuchungen iiber Uredineen,” vol. ii. p. 209, 
Berlin : 1866, 
