The Evolution of the Higher Uredinece. 
IOI 
demands a separate treatment, is excluded from present consider¬ 
ation. It should be noted that, even before its nuclear history was 
properly investigated, Endophyllum was rightly considered to be 
one of the highest forms of the lower group or of the lowest forms 
of the higher group, if with Dietel we suppose the Uredineae to 
consist of two groups, the Pucciniaceae and the Melampsoraceae, 
or, as I have named them, the Pedicellatae and the Impedicellatae. 
Moreover, Hoffmann shows that the basidium of E. Senipervivi, 
sometimes bears more than one basidiospore from each of the 
four cells. He observed as many as eight from one basidium. We 
may conclude that this is the primitive mode of basidiospore- 
formation, resembling in that respect that of the Ustilagineae, 
from the ancestors of which it is generally agreed the Uredineae 
are descended. I have not been able to meet with this mode in 
E. Euphorbias’, in that species, so far as I have seen, there is 
always one basidiospore on each of the four cells. Muller’s 
experience seems to be the same (19). 
We may now take it as established that Endophyllum 
approaches the form of the primitive Pucciniacea, though 
undoubtedly it has a more highly developed peridium. The latter, 
therefore, had on the same mycelium spermogones producing male 
spermatia, and female cells arranged in a more or less cup-shaped 
chamber. At some time or other, either before or after this, 
fertilisation by the spermatia was lost, and the conjugation of two 
equal female gametes took its place. The resulting spores were 
produced in chains, with intercalary cells to facilitate dispersal— 
these on germination produced a basidium and basidiospores, each 
of which could infect the host again, and produce a mycelium 
which again bore spermogones and aecidia. Hoffmann proved that 
this is so in the case of Endophyllum Senipervivi. It may be 
noted that in the Ustilagineae there is, in addition to the conidia, 
only one kind of spore which acts like the teleutospores of the 
Uredineae. 
The sterigmata of Endophyllum are variable in size and indefinite 
in shape. This is itself a sign of a lower stage of evolution; in the 
higher types of the Uredineae the basidium was modified so as to 
produce only one basidiospore from each cell of the basidium and 
on a well-defined sterigma. The life-cycle of Endophyllum may be 
represented diagrammatically, much as is done by Hoffmann, in 
the following scheme:— 
