of the Genus Doassansia , Cornu. 27 
Var. Earlowii (Cornu). 
This form was collected by James Fletcher in Ottawa, 
Canada, and grew on several species of Potamogeton. The 
habit is probably identical with that of the form here described 
as the type. Fletcher, however, says, in a letter to Prof. 
Farlow, that the ovaries are swollen to three or four times 
their normal size, and are of a greenish white spotted with 
reddish brown. He also says that these distorted fruits 
often cracked and fell to pieces, developing a white mouldy 
growth. I certainly found no such behaviour in my speci- 
mens. The embryo of the^pondweed is often found matured 
in specimens of the variety, but is always aborted in my own 
specimens. The alcoholic material of the variety crumbles 
easily, and consists almost entirely of a mass of sori, while 
that of the type form is decidedly firmer. But all these 
may be due to the age of the specimens or to the difference in 
the grades of alcohol used in preserving them, or to some- 
thing of that nature. 
The structure of the sorus is essentially the same in both 
the type and the variety, with the exception that the spores 
of the latter are much elongated radially (Fig. 78) and much 
narrower. The larger spores of the variety measure about 
16 [j. by 3 ju, to 4 (a. The cortical cells are rather smaller than 
in the type. The elongated spores are shown in Cornu’s 
figures (Ann. Sci. Nat. 5, ser. 6, T. 15, PI. 16, f. 5 to 6), where the 
elongated spores are supposed to correspond with the cortical 
cells of D. alismatis , and the sterile cells of the centre of the 
sorus to the spores of that species. 
It may be that this striking variation in the shape of the 
spores is due to Fletcher’s specimens being immature, as Cornu 
supposed them to be. I have been able to examine specimens 
of the original collection made in August, 1882, and alcoholic 
material sent to Prof. Farlow, collected in June, 1884. By 
tracing the development of the sori, which corresponds exactly 
with that described for the type, I have found the same type 
of spore in sori that seemed to be mature. It seems im- 
possible to consider these two forms identical, for they differ 
