134 NEMATOPHYCE. 
are the young spores, which undergo a marvellous variety of transforma. 
tions. At first they are contiguous, but as they contract they become 
free, though variable in shape, and with their chlorophyll distributed in 
a thousand different ways. Finally they become spherical and almost 
completely filled with chlorophyll interspersed with some starch granules, 
and covered with a thin, smooth layer of plastic matter, but not with a 
cellulose membrane. 
“Long before the foregoing process has taken place, the cell-wall 
proper of the thread has undergone some peculiar chemical alterations, 
all tending to its final dissolution to free the fnlly-developed spores, 
Previous to this, however, little apertures are formed in it at certain 
points, varying in diameter from one 500th to one 300th of a line. 
“All the cellules of the same filament do not undergo the modifica- 
tions described. Ina large number of them the phenomena are quite 
different, the green rings, interspersed with colourless vacuoles, 
gradually change to a reddish yellow, and the grains of starch dis- 
appear. Soon the coloured matter thus formed becomes granular, and 
is finally broken up into innumerable rod-like corpuscles.” 
Thus the cycle is completed, and we need not pursue the abstract 
further. Plate ZIJ. will serve to illustrate the various changes. 
Spheroplea annulina. (Roth.) Ag. Syst. p. 76. 
Green, yellowish, brick-red, or scarlet, cells 8 to 10 or 20 
times as long as broad, with 20 to 30 chlorophyllose rings in 
each cell; spores at length densely seriate, rarely disposed 
irregularly, at first green, afterwards olive-brown, and then 
red. 
Size. Threads :036-:07 mm. diam., oospore ‘018-036 mm. 
Rabh. Alg. Eur. iii., p. 318. Rabh. Alg. ex. 309, 455, 147, 
Cohn, in Acad. Berl. 1855, p. 335. Ann. des. Sci. Nat. 4 ser. 
(1856) v., t. 12-13. Cienkowski, Bot. Zeit. (1855), p. 777. 
Fresenius Bot. Zeit (1851), p. 241. Braun, Rejuvenescence 
p. 164, 271, 281. 
Conferva annulina, Roth, Cat. iii., p. 7. 
In quarries, pits, or inundated fields. 
Cohn has remarked that whereas most confervoid Alge vegetate by 
repeated subdivision of the terminal cell, being at some time or other 
attached by the base, the present has both extremities alike, and 
neither of them rooting, moreover the vegetation is carried on by 
sub-division of the central cells, so that the terminal cells remain the 
oldest. 
Plate Lil, fig. 1. Portion of filament of Spheroplea annulina with 
the green cytioplasm in rings X 400. Fig. 2, cells showing the forma- 
tion of spermatozoids X 400 with escaped spermatozoids s below. Fig. 
8, spores having acquired a globose form being fertilized by sperma- 
tozoids. Fig. 5, spores in an earlier stage. Fig. 8, isolated spore with 
spermatozoid attached. Fig. 6, mature spores, having acquired an 
orange colour and stellate outline, the primary membrane is detached 
X 400. Fig. 7, cells showing arrangement of mature spores X 300. 
Fig. 4, resting spore in various stages; a, mature; 5, divided into 2;¢ 
and d, further subdivided. Fig. 9, zoogonidia X 400. Fig. 10, germina- 
tion of zoogonidia X 400. All except Fig. 7 after Cohn. 
