198 THE BOTANICAL MAGAZINE. rvoi. xxxi. No. 307. 



the water, we perceive the " duplicated " portions of leaves only, 

 the other parts of frond being practically shaded under them. 

 In this respect, and in other characters also, the species stands 

 quite near by Turbinaria, and may be well taken as a link 

 between the genus and Sargassum. Compare the accompany- 

 ing photograph (Fig. 1.) and the figures of Turbinaria in 

 Barton's On the Genus Turbinaria, Plate 54 (Trans. Linn. 

 Soc, Ser. 2, Bot. Vol. Ill, 1891), Oltmanns' Morph. u. 

 Physiol., I, p. 509, etc. 



5. Berherifolium J. Ag. and 5. crassifolium J. Ag. have the 

 leaves less duplicated than S. duplication and often quite 

 simple. In S. Sandei the leaves on the lateral branches are 

 generally duplicated in some degree, but the fulcrant leaves are 

 never so Very often the duplication of leaves in this species 

 is limited to the terminal ones of the lateral branches and 

 branchlets, and not unfrequently absolutely wanting. I have 

 ascertained after examining a good number of specimens, that 

 the male plants, as a rule, have luxuriant foliage and poorly 

 or not at all duplicated leaves. These specimens having laid 

 before me, I can clearly demonstrate that the degree of duplica- 

 tion of leaves : 1), is gradual in a range of species ; 2), differs 

 according to the stages of development of frond ; 3) varies 

 according to the parts of frond ; and 4), differs bj' the sex of 

 plant. 



Some of my specimens, as Reinbold has already described, 

 have angulated, spinulated, and cymose receptacles, while some, 

 cylindrical, verruculose and racemose ones. The former is 

 female and the latter, male. It is quite natural that the male 

 form with non-duplicated leaves would be classified in the 

 group Malacocarpicae J. Ag. unless one has been supplied with 

 a complete set of specimens. Hence, specimens of the present 

 species may very likely be found in some herbarium under a 

 specific name which is placed among the Malacocarpicae. It 

 gives an evidence also that the division of the subgenus Eusar- 

 gassum into Acanthocarpicae and Malacocarpicae as done by 

 J. Agardh can not be but inadequate and unreliable. 



In the Agardhiau Herbarium a specimen with spinulated 



