CHROOLEPIDEZ. 185 
whilst the outer ones are green. The reddish brown granules seem 
to be oil drops A great number of the threads terminate with a globose 
much thickened cell, which subsequently becomes the mother cell of 
the zoospores This mother cell is rarely foand in the middle of the 
threads. Occasionally, but still more rarely, the cell immediately under 
the mother cell elongates itself sideways and upwards into a thread. 
The mother cell of the zoospores, when it forms the terminal cell of 
the thread, bears a conical massof gelatine, often of considerable size, 
which, however, ig seldom on the crown of the cell, but usually at its 
side. In those mother cells in which the zoospores are about to escape 
a division of the coutents into small oval cells is clearly perceptible, 
andat the side, or near the top, the wall is extended into a short 
papilla. The contents emerge in the form of a well defined vesicle, 
with the zoospores penetrating through the ruptured papilla, some- 
times, however, no vesicle is formed. Afew moments after emerging 
the vesicle bursts, doubtless by absorption of water, and the zoospores 
swim about in every direction. The remnants of the vesicle are of a 
gelatinous nature. The escape of the zoospores was observed from nine 
in the morning till four in the afternoon, and seems to depend not upon 
the influence of light, but solely upon the effect of mvistening with 
water. The zoospores are very small, ‘0035-0033 mm. They are 
filled with reddish brown granular matter, the apex alone being free 
and hyaline; there are two cilia, about three or four times as longas 
the spore. The apex with the cilia is directed forwards. They rotate 
perpetually whilst swimming; their motion being so rapid as to prevent 
a clear view of them, except when stopped by some obstacle, or when 
their motion is becoming retarded. The cell is surrounded by a clear 
highly refractive border looking like gelatine, but which may be only 
an optical appearance. After continuing in motion for about an hour 
the zoospores become sluggish, sink, become globular, elongate them- 
selves, and shortly a division of the cell takes place by a transverse 
septum. Some reddish brown granules usually remain behind in the 
empty mother cell, and in the remnant of the vesicle. Oftentimes 
some z.0spores cannot emerge from the mother cell, and then they 
sometimes germinate in it. These observations were made on a variety 
of Chroolepus aureus. Quart. Journ. Micro. Science, viii. (1860), p. 
159, 
Chroolepus aureus. (Linn). Kutz. Tad. tv., t. 93. 
Golden red or orange. Threads either collected in small 
tufts, or spreading in a soft silky stratum, sometimes intricately 
and densely expanded and very much branched. Cells as long, 
or two to three times as long as their diameter. 
Sizz. Cells -01--012 mm. diam. Zoosporangium *02 x 
°03 mm. 
Eng. Fl. v., p. 380. Eng. Bot. ii, t. 2528. Harv. Man. 
189. Mack. Hib. 246. Rab. Alg. Hur. iii., 371. 
Conferva aurea, Dillw. Conf. t. 35. 
Byssus aurea, Eng. Bot. i., t.212. Lightf, Fl. Scot. p. 1002. 
Hull Br. Fl. 307. Relhan Cant. 446. Huds. Fl. Ang. 606. 
Sibth. Ox. 338. Purton Midl. Fl. ii., 606. Ray. Syn. 56, No. 
6. Abbot Bedf. 276. With. Arr. iv., 144. 
Ceramium aureum, Hook. FI. Scot. ii., 86. 
Amphicomum aureum, Johnst. Fl. Berw, ii., 243. 
