ARCHER, ON SAPROLEGNIEZ, 123 
minal opening, were obseryed—so far characteristic of Sapro- 
legnia. 
Setting aside, however, the generic characters, this plant 
is specifically characterised (I believe from every other Sapro- 
legniaceous plant yet described) by its true fruit, in the fol- 
lowing manner : 
Saprolegnia androgyna, sp. nov. Fig. 1. 
Plant monecious ; oogonia large, barrel-shaped or elliptic, 
mostly in an uninterrupted terminal series, though occasion- 
ally interstitial ; the terminal oogonium the oldest in a series, 
the oogonia thus showing gradually different degrees of de- 
velopment down to the basal one, which is the youngest ; the 
lateral male branches (Nebeniiste, Pringsheim), with the ex- 
ception of those fertilismg the lowest oogonium of a series, 
are not derived either from the principal stem of the plant 
or from any neighbouring portion of the general plant, but 
these are given off from the oogonium itself, which is next 
immediately beneath the oogonium which is fertilised by 
them, and so on down to the lowest or basal oogonium of a 
series, to which last are given off lateral male branchlets from 
the original filament or stem immediately thereunder. The 
tube or cavity of each lateral male branchlet becomes shut 
off by a septum formed a short distance above its origin, the 
portion of the contents above the septum being developed into 
the male element—that portion of the contents below the 
septum retaining its characters, and being returned back into 
the oogonium, whence it originated, in time to become em- 
ployed, with the remainder of the contents, in the formation 
of the oospores. Oospores large, about ~!,th of an inch in 
diameter, mostly numerous, but very variable in number, 
sometimes, though rarely, as few as even one. They occasion- 
ally exhibit what appears to be a roundish excentric vacuole. 
The whole plant large and coarse as compared with other 
described forms in this family. 
If thus, for sake of illustration, we call the upper (mostly 
terminal) oogonium A, that beneath it B, that beneath the 
latter C, and so on down, let us suppose, to G; then oogo- 
nium A is fertilised by the lateral male branchlets emanating 
from and in direct continuation with B; the oogonium B is 
fertilised by the lateral male branchlets, in the same way, 
emanating from C, and so on down to F, which is fertilised 
by the male branchlets emanating from G; but G is itself 
fertilised by the lateral male branchlets emanating from the 
supporting stem, for G has no oogonium beneath. So, of 
the whole chain of oogonia, the oospores in each, the lowest 
one excepted, are fertilised by the male elements derived from 
