Uredospores. 33 
3 
growths, which become globose and filled with endochrome 
(reserve spores) (Plate III. Fig. 14), These abnormal phe- 
nomena show how nearly allied the different spore-forms 
of the Uredinee are; and are especially interesting from 
an evolutionary point of view. They show that although 
the uredospore has attained a definite mode of germination 
proper to itself, yet it has not entirely lost its capability 
of reverting to, and simulating the mode of growth of 
other spore-forms.* 
In certain species (Lecythea) are found bodies known 
as paraphyses, or cystidea. They are in most cases arranged 
around the circumference of each spore-bed, arching over 
it and arising from basidia in the same manner as the 
spores themselves. The paraphyses contain no coloured 
endochrome. In shape they may be globose, pyriform, 
subcylindrical, or capitate (Plate III. Figs. 16, 17). 
Although they cannot be regarded as undeveloped spores, 
inasmuch as they are pretty much confined to particular 
species, and do not occur indiscriminately with all, yet 
from their mode of origin their affinity is clearly with the 
pseudoperidial cells of the zcidiospores, and to a certain 
extent they are protective organs in the same way as the 
latter. From my observations it appears that the presence 
of paraphyses with certain species greatly depends upon 
some special condition of the fungus, as they may be 
absent, or nearly absent, according to special circumstances. 
I find them constantly present with the uredospores of 
P. perplexans, when these have arisen not directly, but rather 
at a considerable distance, from the zcidiospores. On the 
other hand, when the uredo arises directly from the ecidio- 
spore, they are hardly present at all; this looks very much 
as if they were an indication of exhaustion of vital energy 
* Tulasne figures a similar condition in the germination of the uredospores 
of Cronartium (“ 2° Mémoire,” tab. xi. figs. 3, 8, 9). 
D 
