BOT.— Vol. II.] HUS—rORPHYRA. 1 87 



either cubical or more frequently higher than broad, the 

 vegetative cells of the fronds of the distromatic species 

 vary, as a rule, from cubical to broader than high. Excep- 

 tions to this rule are found in P. nereocystts, a monostromatic 

 species which sometimes possesses cells which are broader 

 than high, and in P. variegata. While the vegetative cells 

 of the younger sterile fronds of the latter species are usually 

 square, the vegetative cells of the older fertile fronds are 

 much higher than broad and often have a fusiform appear- 

 ance. Judging from the fact that the vegetative cells are 

 found between the reproductive cells, it is suggested that 

 the shape of the former is due to pressure exerted by the 

 reproductive cells, which before dividing gorge themselves 

 with protoplasm, and when fully ripe swell to an abnormal 

 size, owing to the partial dissolution of the jelly partitions 

 separating the individual spores. 



During the study of the species of Porphyra of the Paci- 

 fic Coast, the fact gradually made itself felt that the repro- 

 ductive bodies are of the greatest diagnostic value, and that 

 habitat, color, and thickness of frond can only be used to 

 determine species in connection with the number of divi- 

 sions of the antheridia and sporocarps. 



Since the object of this paper is merely to give a syste- 

 matic account of the species of Porphyra of western North 

 America, and it is not designed to throw light on the sexu- 

 ality or nonsexuality of the genus Porphyra, the author uses 

 the terms sporocarp and antheridium merely to indicate the 

 larger and smaller bodies, which by some are believed to 

 play a part in sexual reproduction, without necessarily 

 ascribing a sexual character to these bodies. The same is 

 true for the asexuality of the monospores. But it must be 

 said that in no case even the slightest indication of sexuality 

 has been observed, though many sections of sporocarps in 

 all stages of development were examined. Neither has the 

 author been able to observe an amoeboid movement of the 

 liberated carpospores, nor flagelliform appendages to the 

 bodies contained in the antheridia, nor any movement on 

 the part of these bodies, though observations were made to 



