CHYTRIDIE. 199 
“The Chytridia form a genus of unicellular, parasitical Algz, or, if it 
be preferred, of aquatic Fungi, related to Saprolegnia about as much as 
Ascidium is to Bryopsis. The entire plant is composed of a single balloon- 
shaped cell, which penetrates into the Alge upon which it grows, by a 
more or less developed root-like base. The inflated portion of the cell is 
filled with colourless mucilage, from which are formed, not through suc- 
cessive division, but by a simultaneous process, very numerous small 
globular germ-cells, which exhibit a sharply-defined darker nucleus in the 
interior, and possess a single very long cilium, From their want of 
colour and the activity of their motion these gonidia resemble the most 
minute monads. Their extrusion occurs either through the casting off of 
a lid or through mere tearing of a nipple-shaped point. Of fifteen different 
species which I have observed in the vicinity of Freiburg, Chytridium 
olia is the largest, and at the same time exhibits the lid-like dehiscence 
most beautifully. It grows on the anterior wrinkled end of the bulging 
parent-cells of the spores of Gidogonium Landsboroughii, the root pene- 
trating into the folds and attaching itself to the spore. The free inflated 
portion of the cell is ovate, with the lid somewhat thrown up at the 
edges, and apiculated like a short nipple in the middle. The germ-cells 
are about ‘003 mm. diam.”—Braun, Rejuvenescence, pp. 186 note. 
See also Braun, ‘ Ueber Chytridium ” (Berlin, 1856); Cohn in “ Hed- 
wigia,” 1865, p. 170 ; Nowakowski “ Beitrag zur Kenntniss der Cbytri- 
diaceen’ (Breslau, 1876). 
Chytridium acuminatum. Braun Chytr. p. 28,t.1, f 11. 
Cells much smaller than in Chytridium olla, ovate-pyriform ; 
operculum acuminate. 
Size. Cells -016 mm. long. 
Rabh. Alg. Eur. iii., p. 277. 
Parasitic on species of Gidogonium. 
Plate LXXXI. fig. 1. Chytridium acuminatum parasitic upon Edo. 
gonium Rothit X 400 diam. 
Genus 77. RHIZOPHYDIUM. Schenk. (1858.) 
Cells globose, ovate, or broadly clavate, with 2, 8, or more 
scattered orifices, more or less elongated into a neck, furnished 
with, or destitute of, distinct radicles at the base. 
Rhizophydium Barkerianum. (Archer.) Rabh, Alg. Eur. 111. 281. 
Cells much depressed, 3 or 4 lobed, the lobes broadly rounded ; 
upper surface of the cell concave, bearing at the centre a ver- 
tical hyaline, very slender, terete, minutely capitate process ; 
cell contents mainly confined to the centre, leaving the ends of 
the lobes empty; zoospores making their exit through the 
opened apices of the lobes. 
Chytridium Barkerianum, Archer in Quart. Journ. Micr, Sci. 
1867, p. 89. 
Parasitic on Zygnema. Callery Bog (Ireland). 
We have seen no specimens, and are not aware of any figure extant, or 
of any dimensions having been recorded. 
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