THE rUCACE^ Oi' JAPAN. 14*J 



recognized the close relation between his species and Sargassum 

 Ruiggoldhumm Harv., but did not observe the difference in 

 full. Afterward, in Anal. Alg. cont. III., p. öl, he described 

 a plant in detail which he identified with Hakvey's species. 

 He seemed to have had great doubts on the validity of his 

 species when he wrote the latter paper. The distinguishing point 

 between his and Harvey's species lay essentially in the characters 

 of the receptacles. De Toni^^ also notes the strong resemblance 

 of the two species when he says " Huic speciei {S. Ringgoldianuni 

 Harv.) paraffine videtur Sargassum coreanuiii J. Ag." It is not 

 hard to see from J. Agardh's later publication-' that he was 

 very uncertain as to the propriety of describing them separately. 



I have seen authentic specimens of neither J. Agardh's nor 

 Harvey's species. I am, however, strongly of the belief that I 

 am not in error in referring our plant to the above named 

 species, which has no confusable form on our coast. The re- 

 ceptacles differ in external form according to the sex as described 

 above. J. Agardh's description of Sargassum coreanum I 

 have found satisfactorily applicable to the female plants ; while 

 the description of Sargassum Ringgoldianum in Anal. Alg., 

 1. c, applies very well to the male individuals. I therefore do 

 not hesitate to say that J. Agardh described the sexually 

 differing forms of Sargassum Ringgoldiaimm Harv. as two distinct 

 species. 



The differences in the vegetative characters of male and 

 female individuals are quite negligible. A difference, if any, 

 will be found in the crown leaflets of the vesicles. In the 

 male, abruptly truncated leaflets predominate, while in the other, 



1) I'liyc. Jap. Nov. p. 44. 



•1) Anal. A1-. Cont. III. p. 51-52. 



