CHROOLEPIDE.E. 185 



whilst the outer ones are greeii. 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 found 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 mass of gelatine, often of considerable size, 

 which, however, is 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 contents into small oval cells is clearly perceptible, 

 and at 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. A few 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 moistening with 

 water. The zoospores are very small, 'OOSo-'OOSS 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 long as 

 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 zoospores 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, vin. (1860), p. 

 159. 



Chxoolepus aureus. (Linn). Kutz. Tab. iv., 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. 



SIZE. Cells 'Ol-'Ol^ 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. Eur. iii., 371. 



Conferva aurea, Dilhv. Conf. t. 35. 



Byssusaurea, Eng. Bot. i., t. 212. Lightf. Fl. Scot. p. 1002. 

 Hull Br. Fl. 307. Relhan Cant. 446. Huds. Fl. Aug. 606. 

 Sibth. Ox. 338. Purton Midi. Fl. ii., 606. Ray. Syn. 56, No. 

 6. Abbot Bedf. 276. With. AIT. iv., 144. 



Ceramium aurewn, Hook. Fl. Scot, ii., 86. 



Amphicomum aureum, Johnst. Fl. Berw. ii., 243. 



