on Saprolegniccte. 341 
and simulating a gigantic nucleus. These granules stain deeply 
with nuclear stains (borax carmine, haematoxylin, nigrosin), 
and are obviously nitrogenous (can they be the undigested 
nuclein derived from the nuclei of the host ?). The pseudo- 
podia are retracted, and the body rounds off and becomes 
spherical. At this and subsequent stages of the zoocyst a 
long flagellum may be protruded, giving rise to the sluggish 
movements of the body (Figs. 14, 15), seen by Lindstedt. The 
spherical mass soon becomes infested by a membrane, which 
is probably chitinous, as it neither swells nor stains blue in the 
Schultze solution of iodine. It is in this stage, that of the 
‘ zoocyst, ’ that the species has been noted by my predecessors. 
Zoocysts may be found lying free in the debris of old cultures 
as well as inside the hyphae. In my balsam mounts of Sapro- 
legnieae these zoocysts frequently occur slightly or not at all 
stained. The stain I use is borax carmine and nigrosine, followed 
by treatment with acid alcohol for differentiation, so that the 
parasite is possibly more readily decolourised than the fungus. 
When well-stained the excrementitious mass is often even darker 
than the nucleus, which still retains the characteristic rhizopod 
type. From comparison of successive stages (Figs. 9-13) in 
stained preparations we find that the nucleus then undergoes 
complete bipartition to form from four to sixteen — usually 
eight — daughter nuclei ; which soon become regularly distri- 
buted through the protoplasm. The latter then divides 
according to one of two ways : either the vacuole around 
the faecal mass sends directly radiating processes outwards, or 
else radiating vacuoles appear in the plasma and open first 
into that surrounding the faecal mass before they extend to the 
periphery, and so divide the plasma into wedge-shaped masses. 
These are the zoospores. One of these bores through the 
cyst-wall, and the others follow through the same hole; no 
discharging process is formed as in Chytridieae and Sapro- 
legnieae themselves. The zoocyst- wall persists ; but the 
excrementitious mass left within soon disintegrates and dis- 
appears (Figs. 14, 15). Hyphae attacked by Woronina 
polycystis , may also be attacked by our parasite, which lives 
