Methods of Reproduction in the Saprolegniacece. 191 
sporocyst; this process is usually repeated several times, giving the 
appearance known as “ nested sporocysts.” 
Zoospores, unicellular, discharged in the motile state and 
immediately disperse by active swarming; they are diplanetic. 
The first form, egg-shaped, with the apex drawn out into a point 
bearing out two terminal cilia, comes to rest after a few minutes 
becomes spherical and secretes a membrane. After a short 
resting period, the contents creep out and forms a new zoospore. 
This second form of zoospore is kidney-shaped, with two lateral 
unequal cilia, swarms for a longer period and later germinates to 
form a mycelium. 
Oocysts, usually terminal, but sometimes intercalary, or 
variously arranged; chiefly borne in clusters, which may occur 
terminally on the main hypha, but more usually on short lateral 
branches arising from it. The oocysts are spherical, pear- or 
barrel-shaped, smooth or spiny, usually spotted, and have a 
moderately thin membraue. In most species the oocyst contains 
many oospores, but in some species the oocyst regularly contains 
only one oospore; this condition may also occur as a variation in 
species which usually have many ova. 
Antherocysts, egg- or curved club-shaped structures of small 
size, borne terminally on an antheridial filament (Nebenasten), 
which may arise either from the main hypha bearing the oocyst 
(androgynous), or from separate branch of the main hypha (dik- 
linous). In some cases it is cylindrical and arises from the same 
branch which bears the oocyst (hypogynous). 
When the antherocysts are not present, the oospores nearly 
always mature parthenogenically. The oospores are spherical, 
smooth, with a thick, coloured, glistening exospore and a thinner 
endospore, and brown or yellow contents with a concentric or 
excentric globule of fat. 
Gemmae of very different sizes and shapes often occur, 
Genus Apodyn, Cornu. 1872. 
Mycelium composed of hyphae, monopodially branched in the 
same manner as Snprolegnia, but divided into cylindrical segments 
by constrictions at approximately equal intervals. 
The segments thus formed are not separated by definite 
transverse walls, but each segment contains one or more disc¬ 
shaped cellulin bodies, usually situated in the neighbourhood of 
the constriction. 
