4 Brannoii. — The Slrtichire and Development of 



The female plants average larger than the tetrasporic. Their 

 cystocarps are arranged promiscuously on either side of the 

 frond, while occasional sections through cystocarps growing 

 base to base were obtained. The cystocarps are cone-shaped, 

 with carpostomes in the crown of each affording a place 

 through which the mature carpospores may escape. Within 

 the fully-developed conceptacle, dichotomous chains of lake- 

 red, slightly elliptical carpospores are readily seen by focussing 

 through the pericarp ; but the carpospores are so numerous, 

 so densely massed together, and of such deep colour in the 

 mature cystocarps, that one can determine very little of 

 the true structure of this organ by means of optical sections. 

 As in the non-sexual plants, the fruiting-bodies in the male 

 and female frond are less mature near the margin and apex. 



On certain cystocarpic plants numerous proliferations are 

 developed on both sides of the frond. These plants are 

 apparently healthy and normal in all other i-espects. The 

 proliferations may become greatly developed and give the 

 plant an unusual appearance, very similar to that of leaves 

 bearing many small galls. These outgrowths are composed 

 usually of from two to three axial rows of cells corresponding 

 to those of the frond, except that their contents are clear and 

 granular. These cells are surrounded by one or two layers 

 of smaller cells, having the characteristic lake-red colour of 

 the frond (Fig. 14). An unusually fine opportunity for the 

 study of the origin and development of the cystocarp is 

 offered by these proliferations (Figs. 3, 14, 17). They were 

 critically examined in whole and sectioned preparations, in 

 stages from the earliest formation of the procarp to the 

 mature cystocarp. The cystocarps thus developed often 

 appeared pedicellate on account of the length of the prolifera- 

 tion, in the outer end of which they were borne (Fig. . 3). No 

 tetrasporic or antheridial plants were found bearing these 

 proliferations. 



The asexual plants outnumbered the female even during 

 July and August, the period when the latter reached their 

 maximum number at Woods Hole. In shape, colour, and 



