RHODOPHYCE^E, OR FLORIDE^E 203 



branches, constituting the antheridia, are often col- 

 lected into groups covering portions of the surface of 

 the thallus. The surface may be depressed where they 

 occur, and sometimes even flask-shaped cavities are 

 formed, recalling the spermogonia of lichens (Fig. 84). 

 The actual male cell itself is quite colourless but 

 always nucleated. When ripe it opens at the apex 

 and the contents issue forth as a round pollinoid, some- 

 times with a beak-like projection, and always with a 

 nucleus. The occurrence of pollinoid cells in series, 

 one above the other, in certain antheridia may be 

 due to intercalary bipartitions, but possibly, on the 

 other hand, to the successive abstriction of terminal 

 cells which have remained attached in a chain. 

 After the emission of the pollinoid, the supporting 

 cell sometimes grows through and develops another 

 male cell within the empty wall of the original male 

 cell. No cilia have ever been detected on this mem- 

 braneless pollinoid, though Schmitz and other ob- 

 servers have rioted appearances that suggest the 

 existence of some such organs. Guignard's recent 

 observations, however, leave little doubt that the 

 pollinoids are without cilia, and, moreover, that in 

 some cases at least they are provided with a mem- 

 brane at the time of their escape. So far as is 

 known, however, they are wafted by the water much 

 as the pollen grains of flowers are blown by the wind, 

 and they do not usually become invested with a mem- 

 brane until they reach the female organ. 



The carpogonium itself is a single cell drawn out 

 at one end into a long fine hair called the trichogyne, 

 which projects from the surface of the thallus, and 



