GERMINATION AND GROWTH. 145 
production of cylindrical tubes, which start from the upper 
extremity of the wedge-shaped spores, or more rarely from the 
base. These tubes are straight or twisted, simple or bifurcated, 
and each of them very soon emits four monosporous spicules, at 
the same time that they become septate. The sporules are in 
this instance globose. 
In Uromyces germination follows precisely 
the same type as that of the upper cell of 
Puccinia ; in fact, Tulasne states that it is 
very difficult to say in what they differ from 
the Puccinie which are accidentally unilo- 
cular. 
In Cystopus a more complex method pre- 
vails, which will be examined more closely 
hereafter. 
In Puccinia, as already observed when 
describing their structure, the pseudospores 
are two-celled. From the pores of each cell, 
which are near the central septum, springs 
a clavate tube, which attains two or three 
times the total length of the fruit, and of 
which the very obtuse extremity curves 
more or less in the manner of a crozier.* 
This tube, making a perfectly uncoloured 
nf E Fic. 84. — Germinating 
transparent membrane, is filled with a pseudospore of Uromyce 
: ( 
granular and very pale plastic matter at (Peemdicwlatus, (Tulasne.) 
the expense of the generative cell, which is 
soon rendered vacant; then it gives rise to four spicules, usually 
on the same side, and at the summit of these produces a reni- 
form cellule. The four sporules so engendered exhaust all the 
protoplasm at first contained in the generative cell, so that their 
united capacity proves to be evidently much insufficient to con- 
tain it, the more so as it leads to the belief that this matter 
undergoes as it condenses an elaboration which diminishes its 
size. In all cases the spicule originates before the sporule which 
it carries, and also attains its full length when the sporule ap- 
* Tulasne, in his ‘‘ Memoirs on the Uredines.” 
