too 
W, B. Grove. 
mycelium, even within the aecidial cup, as in U. Cunniugha- 
tnianus (2), or close to its margin, as in Puccinia Berberidis (6), or 
in a circle round it, as in Uromyces Belienis. The pedicel of the 
uredo- and teleutospore is the homologue of the intercalary cells 
of the aecidiospore-chain. In the sori of the primary uredospores 
of Phragmidium Potentillce-canadensis (= Pli. Tormentillcc Fckl.) 
the basal cells act as in the formation of aecidiospores, but the 
lower sterile half of the spore-mother-cell, instead of disintegrating, 
elongates to form the pedicel of the uredospore. Large hasal cells, 
similar to those occurring in the aecidium, are frequently found in 
the sori of uredo- and teleutospores. In many of the lower 
Uredineae those two kinds are produced in chains. In Chrysomyxa, 
aecidio-, uredo-, and teleutospores are all concatenate. We have 
thus various requirements to be satisfied by any explanation of 
the origin of these spores: is it possible to reconcile them all ? 
Endophyllum. 
The genus Endophyllum comes to the rescue, especially since 
the recent investigations of Hoffman (14). He shows that Endo¬ 
phyllum Sempervivi has only one kind of spore in addition to the 
spermatia and basidiospores. This is produced in a cup exactly 
like an aecidium, in chains with intercalary cells, from a basal 
fertile cell with two nuclei, which arises as in Phragmidium, etc., 
by the fusing of two of the cells of the fusion-tissue after the 
manner described by Christman (5); the two which fuse are 
adjoining cells of the same mycelium (not situated in any definite 
plane), but presumably never of the same hypha. The pair of 
nuclei then divide in the well-known conjugate way, the aecidio- 
spores thus all containing at first two non-sister nuclei which 
afterwards fuse as the spore approaches maturity. This fusion has 
been denied by Sapin-Trouffy and Maire, but evidently as the result 
of mal-observation : their mistake has led to several unfounded 
conjectures about Endophyllum. The aecidiospore germinates as 
soon as mature with a basidium and basidiospores, like an ordinary 
teleutospore of Puccinia, the fusion-nucleus having sooner or later 
divided twice, the first being the reduction-divivision. The spores 
of Endophyllum Euphorbia: do the same. 
Obviously these spores are at once aecidiospores by the mode of 
their formation, and teleutospores by the mode of their germination. 
Here, then, is one at least of the ancestral types oospore among 
the higher Uredineae; the lower group, the Melampsoraceae, which 
