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either spherical, oval, or subreniform. Fig. 20 shows a recent spore, Puccinia 
epilobii, D.C., producing these secondary spores.t 
Uredinoid Germination.—The Uredo spore is essentially ephemeral in its 
nature, and does not retain the power of germination for any great length of time. 
The germ-tubes which are thrown out by Uvedo spores are destined to penetrate 
the tissues of the living plant upon which the parasitic fungus grows, their main 
function being not the production of secondary spores, but the direct reproduction 
of the parasite. They invariably, I believe, germinate the same year they are 
produced. This mode of germination is met with in Uredo, Trichobasis, dicidium, 
and Peridermium. In order to save repetition, however, the following is a de- 
tailed account of the process of germination observed in Uredo linearis, Pers., 
during the month of August, 1881, and is not based upon a single experiment, but 
is the outcome of a great many observations made at the time stated. When the 
spores of this fungus, which are more or less ovoid in form, are sown upon a drop 
of water on a glass slide, and placed under a bell-glass, so arranged that the 
atmosphere within the bell-glass is full of moisture, they very soon begin to ger- 
minate. As early as five hours and forty minutes they were found to have thrown 
out two germ tubes, one from each side of the long diameter of the spore, near its 
centre (fig. 1). Sometimes only one tube was observed, but generally there were 
two. These tubes were hyaline, and filled with very pale yellow endochrome from 
the interior of the spore, and were of uniform diameter, as nearly as possible, 
throughout their entire length. Asa rule, only one of these two twin tubes went 
on growing, i.e., increasing in length. When the major tube attained a length 
equal to several times the diameter of the spore from which it sprang, it took a 
series of spiral turns from right to left or vice versd. At this stage the tube pre- 
sented a uniform diameter from end to end, but very soon the basal portion of it 
became enlarged and empty, and soon afterwards, at a short distance from the 
spore, a septum appeared, which cut the empty base of the germ spore from the 
remainder. Before, however, this septum made its appearance, the abortive germ- 
tube became quite empty. and the greater portion of the endochrome contained 
within the spore itself was transferred to the growing tube (fig. 4). This transfer- 
rence of endochrome from the interior of the spore to the growing germ-tube 
always took place. The yellow granules were plainly to be seen moving towards the 
distal extremity of the tube. Sometimes they were more diffused than at others, 
but the great bulk of endochrome was always to be observed nearest the distal 
extremity, not always, however, at the extreme end of the tube, but often a short 
distance from it (fig. 4). The active tube continued making spiral turns upon itself 
like a corkscrew. The actual number of turns varied, as did their direction, 
whether from right to left or left to right. Very often, too, the tube would turn 
two or three times in one direction, and then, reversing its movements, take a few 
turns in the opposite direction. The diameter of the helix, too, was subject to 
considerable variation. The sides of the tube were parallel to each other, and its 
diameter uniform. At the extreme end, which was blunt, there now appeared 
+The subject of puccinoid germination is fully treated of and well represented in ‘‘ Fungi 
their Nature, Influence, and Uses” (Cooke and Berkeley), p. 143—149. 
