162 DIVISION II.—COURSE OF DEVELOPMENT OF FUNGI. 
very thick, and many-layered membranes, the outer layers of which, the epi- 
sporium, are coloured and sclerosed in many species, in some are furnished with 
wart-like or slender spike-like prominences; they may also be known by their very 
dense protoplasm containing a large quantity of fatty matter uniformly distributed in 
small drops or granules, as in species of Synchytrium, or aggregated into a few drops 
or into one comparatively large round drop, as in Polyphagus, Chytridium Brassicae, 
Wor., Rhizidium mycophilum, A. Br., Chytridium Olla. The resting-spores remain 
dormant for some time before germinating. 
If we next endeavour to form an idea of the course of development in the 
Chytridieae, we shall find that our present knowledge permits of our distinguishing 
four types, which might perhaps be combined by pairs into two main types. Each 
of these has one or more chief representatives, and each of these again has a crowd 
of imperfectly known forms doubtfully associated with it. There are no distinctly 
intermediate forms between the two types. 

FIG. 78. Polyphagus Euglenae. A swarm-spore with sphere of fatty matter and nucleus. B young plant grown from a 
swarm-spore with a branch of the rhizoid attached toa resting Fug ec ii with formation of spores just 

completed and resting on the empty mother-vesicle 2 (prosporangium) from which it has proceeded ; on the vesicle are three 
'hizoid-b ‘h D ji ion; @ the ptive individual, 4 the supplying indivi $ the swollen end of the tube of 
conjugation connecting @ and 4, which end is becoming the rudiment of the resting spore, ee the Exgl/enae attacked by the 
Polyphagi, E a portion of the pair shown in D 54 hours later than D; & and s indicate the same parts as in D, 6 empty, s 
mature. After Nowakowski. .4 magn. 550, B, D, E 350, C about 4oo times, 

Section XLVII. 1. Rhizidieae. One species belonging to this section, 
Polyphagus Euglenae, a parasite upon resting Euglena viridis, has become the 
best-known of the Chytridieae through Nowakowski’s beautiful investigations (Fig. 
45). The swarm-spore when it has come to rest in the water becomes spherical 
in shape, and at once puts out hair-like tubular-rhizoid processes in indefinite 
directions (2). If one of these encounters a resting Euglena (e), it penetrates into its 
body, destroying and exhausting it to supply food to the parasite. The parasite 
then begins to increase in size, the rhizoid-tubes become larger and thicker, and 
mew ones are formed which throw out branches, and attack and destroy any new 
