138 
ON THE GERMINATION OF THE UREDINES. 
it has become septate, and are either spherical, oval, or subreni- 
form. Plate 159, fig. 20, shows a recent spore, Puccinia epilobii, 
D.C., producing these secondary spores.* 
Uredinoid Germination. — The Uredo spore is essentially ephe- 
meral 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 Uredo spores are destined to penetrate the tissues of the 
living plant upon which the parasitic fungus grows, their main 
fanction 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 germi- 
nation is met with in Uredo , Trichobasis , AZcidium, and Perider - 
mium. In order to save repetition, however, the following is a 
detailed 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 germinate. 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 (plate 159, 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. As a 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 versa. At this stage the tube presented 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 (plate 159, fig. 
4). This transferrence 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 ex- 
tremity 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 
* 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. 
