ROLLESTON, ON NUCLEATION OF BLOOD-CELLS. 127 
one occasion a curious depressed and equally lobed form of 
these cornua presented itself (fig. 4, the second oogonium to 
the right near the base). ‘This reminds one somewhat of the 
form of the oogonium in idogonium Itzigsohnit (de Bary) ; 
and to those who have seen that plant in fructification the 
comparison will at once call to mind the figure of this peculiar 
lobed extension. I, of course, mean to institute no further 
comparison between them. This new species, too, seems thus 
quite distinct from Achlya dioica by the character mentioned. 
A. dioica has globular oogonia, destitute of cornua, and are 
seemingly always solitary—in fact, so far as they go, quite 
like those of Saprolegnia monoica, except that they are 
smaller. The projecting cornua call to mind the similar but 
smaller ones of Aphanomyces stellatus (de Bary);* but 
setting aside the evidence of this plant belonging to the 
genus Achlya, all the species of Aphanomyces described are 
moneecious, that is, furnished with lateral male branchlets 
emanating from another part of the filament. As regards 
Saprolegnia asterophora (de Bary),t even setting aside, as in 
the previous comparisons, the evidence as to the generic 
location of this plant in Achlya, it is again well distinguished 
by being dicecious, whilst Saprolegnia asterophora is, like 
Aphanomyces stellatus, moncecious. It is, besides, different 
from all these forms mentioned by its larger and coarser size, 
as well as often producing several oospores in the oogonia, 
whilst all the species referred to very rarely produce more 
than a single oospore. 
Nore on the Buoop-corpuscuEs of the trwo-roED SLOTH, 
CHoL@pPus DipactyLus. By Prorsessor RoLuzEston. 
Mr. H. N. Mosetey, of Exeter College, called my atten- 
tion a few days ago to the appearance of nucleation which a 
slide of the dried blood-corpuscles of the Two-toed Sloth, 
Cholepus didactylus, presented under a quarter-of-an-inch 
object-glass of Powell and Lealand’s. I had a short time 
before met with a statement in the recently published second 
part of Dr. Kiihne’s ‘ Lehrbuch der Physiologischen Chemie,’ 
p- 195, to the effect that only some mammals, the sloth 
* ¢ Jahrbiicher fiir wiss. Bot.,’ Bd. ii, p. 178, t. xix, 1—13. 
+ Loc. cit., p. 189, t. xx, 25—27. 
+ ‘Lehrbuch der Physiologischen Chemie,’ von Dr. W. Kihne, p. 195 :— 
