294 T. H. BUFFHAM ON ANTHERTDIA. 



mouth, August, 1890) in fresh condition I noticed that the 

 clearer spots, about 20 /a in diam., were rather larger than the 

 ordinary cortical cells, and in some cases two or three were 

 together. In these were observed minute dots, and below these 

 a larger body (Fig. 9). A section shows the usual structure of 

 a simple antheridium in which a basal cell produces four smaller 

 cells above it, and these may, either at once or by again divid- 

 ing vertically, produce the elongated bodies that actually put 

 forth the pollinoids. As the last-named corpuscles were seen 

 emerging from the gelatinous covering (Fig. 10) I think there 

 can be no doubt that these are the male organs of this plant. 



In Gracilaria confervoides Grev. I found the male plants were 

 small, and beset with numerous short, thin branchlets. The 

 antheridia appear on the surface as circular white spots from 20 

 ja in diam., or elliptical up to 100 fx in major axis by 50 fx in the 

 minor, very numerous, and readily visible with a low power 

 (Fig. 11). They are oldest at a short distance from the base, 

 and very small and immature in the upper portions of the 

 principal filaments. With a higher power it will be seen that 

 this spot is but the thin roof of a cavity, with a delicate ring at 

 the vertex indicating the opening through which the pollinoids 

 are emitted, the sides and bottom of the cavity being 

 uniformly covered with the cells which produce them (Fig. 12). 

 A transverse section of the filament through a cavity shows an 

 ovate or flasked shape, the neck opening on to the surface of 

 the filament. Exquisite figures of this aspect have been given 

 by Thuret and Bornet in Etudes Fhycologiques, PI. 40. (Teign- 

 mouth, August, 1892.) 



The antheridia of Bliodymenia pahnata Grev. were figured 

 by Thuret nearly 40 years ago (Ann. des Sci. Nat., 4me Ser., 

 T. 3, PI. 3) as forming a layer in irregular spots on both sides 

 of the plant. Mr. E. A. Batters collected a male specimen at 

 Berwick, March, 1889. I found several plants (Swanage, etc., 

 June, 1892) in this condition, and noted that they were small, 

 cuneate, generally trifid, about 8 cm. (3 inches) in height, and 

 mottled from near the base to halfway to the upper end by 

 paler spots. But even on a surface view these have a very 

 different appearance from the antheridial layer of any other 

 membranous alga. It will be convenient to compare them 

 throughout with those of Bh. Falmetta Grev., a small specimen 



