JOURNAL OF MICROSCOPICAL SCIENCE. 
DESCRIPTION OF PLATE VIII, 
Illustrating Mr. W. Archer’s papers on “ Asteridia,” on the 
Conjugation of Spirotenia, &c. 
(All the figures x 300, except fig. 12 x 400.) 
Fig. 
1.—Sterile filament of a species of Mougeotia (de Bary, non Agardh) = 
Zygogonium leve (Kiitz.) = Mougeotia levis (Kiitz.), Arch. 
2.— Portion of a pair of conjugated filaments of same, showing the zygo- 
spores formed out of the total contents of each parent cell, and 
massed together in the inflated transverse tube, no septum shutting 
the latter off as a special chamber being formed. 
3.—Portion of a pair of conjugated filaments of same. 
4.—A cell of Penium digitus (Bréb.), containing two Asteridia, seemingly 
formed at the expense of a portion of the original contents of the 
Penium, the residue effete and brown coloured. 
5.—Pair of cells of Spirotenia condensata about to conjugate, the contents 
of each formed into two elliptic masses. 
6.—Conjugation advancing, the outer membrane of the pair of parent cells 
having disappeared. 
7.—The pair of zygospores become round and smoothly defined. 
8.—The pair of zygospores, each showing the commencement of the 
‘honeycomb ”-like externl structure, and each surrounded by 
mucus definitely bounded. 
"igh ee of zygospores fully formed, an optical section (or equator) in 
ocus. 
10.—The same focussed a little up. 
11.—An empty zygospore to show the honeycomb external decoration. 
12.—Zygospore of Spirotenia truncata (Arch.). (x 400.) 
