868 MR. 8. LE MOORE’S STUDIES 
that of water, it is only by the movements of aquatic creatures, 
such as Infusoria, that the precise limits of the Apiocystis can be 
accurately defined. The zoospore marked “y” in this figure bas 
just succeeded in disengaging itself at a point upon the right- 
hand side; while that denoted by the letter “a,” after escaping 
from a point lower down, has got entangled again, and a quarter 
of an hour elapsed before it was able to set itself free. The other 
zoospores followed one by one at intervals, and the gelatinous 
matter dissolved away, leaving the proximal half of the zoospor- 
angium in position: this, in turn, broke down (Pl. LIV. fig. 95), 
the zoospores escaping here in the same way as before. That the 
eavity of the zoosporangium was not obliterated even now was 
proved by the occasional escape of a zoospore into it preparatory 
to its swimming away ; also by the fact that upon focussing down, 
a fresh set of underlying gonidia came into view. When the 
gonidia in fig. 95 had been reduced to the number of eight, a fresh 
supply of water was introduced beneath the cover-slip; and this 
streaming in caused the gelatinous matter to break up and move 
away with the zoospores embedded in it. The only sign now 
that a few hours previously a large zoosporangium with scores of 
gonidia was growing upon the spot is the discoloured point of its 
attachment to the Cladophora-wall; old cells of Cladophora fracta 
infested with Apiocystis may sometimes be seen with several of 
these marks upon them. 
The cell-wall is at first very thin; but after a time its capacity 
for imbibition increases. In this state an inner, more refractive 
portion of the wall ean be distinguished from an outer, consider- 
ably thicker part. The reactions are somewhat peculiar: iodine 
colours the wall only the faintest brown, and this is seen especially 
in the inner portion ; addition of sulphurie acid simply darkens 
the brown stain without imparting to it any tinge of blue or 
violet. With Schulze’s solution a pale brown is obtained. Picrie 
blue does not dye the outer portion, and its blue colour is taken 
up to but the slightest extent by the inner. The whole wall stains 
well with hematoxylin, likewise with saffranin and gentian violet ; 
fuchsin, too, will rapidly coiour both wall and cilia; and this is a 
very good way of bringing the latter into view when their presence 
is doubtful; but on running in dilute glycerine, the colour is at once 
discharged, showing that suberin is not present. Capacity for im- 
bibition continually increasing, the inner highly refractive portion 
ceases to be visible; one would hence imagine that the somewhat 
