1916 Hurd; on Codium 117 



utricle like the beginning of a utricle hair {Fig. 31). The young game- 

 tangium is very blunt and rounded at the tip (Fig. 38). As it grows 

 older it may become more tapering (Fig. 39), or remain broad at the end 

 (Fig. 35). Chlorophyll collects in it until it is densely green. A plug 

 develops in the base, cutting it off completely from the utricle (Figs. 

 38-42). The contents round up into a large number of bright green 

 gametes 12-16 /a in diameter, which contain distinct chloroplasts (Fig. 

 46). The gametangium often contains a considerable number of oil 

 globules. The gametes escape from it by means of the splitting of the 

 tip into two "flaps," one of which is usually seen folded back (Fig. 45). 

 The inside of the gametangium as seen through this opening appears very 

 rough with wart-like protruberances. There may be one, two, or rarely 

 three gametangia on a single utricle, all usually originating at the same 

 level (Figs. 40-42), but occasionally one will be above or below the 

 others (Fig. 39). 



The reproducing area of a Codium plant may extend from the tip 

 to within one or two inches of the base ; but gametangia are most abundant 

 within two inches of the tip. In the great majority of plants examined, 

 gametangia were found no nearer than .5 to 1 cm. from the tip; but in sev- 

 eral cases the}^ were found at the very end. Fig. 38 shows a very young 

 utricle, still terminal, with an almost mature gametangium. Two plants 

 were found with no gametangia within 1.25 cm. of the tip. Very few 

 plants were found not reproducing, some of those only 6 cm. in height 

 bearing abundant gametangia. 



The possibility of parthenogenetic germination of these large gametes 

 is suggested by the failure of all efforts to find the small male gametes 

 supposedly present in this genus. Either these appear at a different 

 period, or they are very rare, or entirely wanting. The former alternative 

 is improbable since no plants were seen which gave evidence of having 

 borne male gametangia or of being about to do so. Collins (4) says that 

 "it is probable that female zoospores of Codium sometimes germinate 

 parthenogenetically." Thuret (19) reported direct germination of "zoo- 

 spores" of C. tomentosum. Hauck (10) describes "Zoosporangien." Ber- 

 thold (2), however, could not get any germination until plants with the 

 larger gametes were grown with those bearing different, smaller gametes. 

 Collins (4), Wille (21), and Ernst (7), ascribe both kinds of gametes 

 to the whole Codium genus. Svedelius (18) reported two kinds of game- 

 tangia on specimens of C. mucronatiim from Tierra del Fuego and West 

 Patagonia. He says that the female gametangia are shorter and broader 

 than the others. Oddly enough, he pictures only female gametangia and 

 female gametes in spite of the fact that the male organs had never been 

 pictured nor adequately described. The only convincing account of the 



