450 BOTANICAL GAZETTE [june 



The growth of these branches which form the pericarp is similar to 

 that of the ordinary subcortical branches. 



On an average 9 carpospores are present in a median transverse 

 section of a mature cystocarp. Often 3 or 4 cystocarps will crowd 

 together, so that in a section they appear as one. The average 

 diameter of the mature carpospores is 38 /x. When the carpospores 

 are actually mature, they are well filled with cytoplasm, contain 

 a large amount of Floridean starch, and a number of protein gran- 

 ules. These granules respond to the stain and to the protein test 

 in the same way as those in the tetrasporangia. These protein 

 granules when they first appear are small and very numerous. In 

 one carpospore in a median section 12 /jl thick there are 170 of these 

 granules (fig. 64). The ringlike chroma tophores, about 2.5 /x in 

 diameter, first appear in the carpospore just before it is mature. 

 They are not peripheral but are scattered throughout the entire 

 protoplast. Chromatophores are often present in the sporogenous 

 filaments and in the auxiliary cells, but have never been seen in the 

 latter at the time the carpospores are formed. It is possible that 

 chromatophores which do not take the stain are present in these 

 cells, although it seems hardly probable that they could be com- 

 pletely overlooked, since the cytoplasm in the auxiliary cell is very 

 thin and much vacuolated. It is generally believed that chromato- 

 phores never arise de novo, and Schmitz (12) has stated that they 

 are always present in the spores of the Florideae. In other 

 Florideae besides Dumontia the chromatophores are evidently not 

 readily seen at this stage, since their presence in the young carpo- 

 spores is rarely mentioned. 



The protein granules in the mature carpospores often disappear 

 just before the spores are discharged, and are never present in 

 the germinating spores. Certain of the chromatophores increase 

 greatly in their staining power coincident with the disappearance 

 of these granules (fig. 65) . There has evidently been some modifica- 

 tion in the substance of these chromatophores, and it seems quite 

 possible that the substance of the protein body is concerned with 

 this change. The chromatophores in the mature carpospores which 

 have thus become differentiated stain with the same intensity as 

 those in the germinating carpospores and appear to have the same 







