Freema)i : observations ox constantinea. 187 



observation contained long internodes. This material was col- 

 lected in late summer. The number of fronds on a branch is 

 also given specific value by Postels and Ruprecht. It is prob- 

 ably of important significance that no tetraspores were found 

 by these authors upon C. rosa-marina but that large numbers 

 were found upon C. sitchensis. Figure 6 represents a young 

 frond having no tetraspores but with a succession of fronds 

 similar to those of C. t-osa-marina, while almost all of the re- 

 maining material had solitary terminal fronds crowded with 

 tetraspores. The material collected in May, 1897, contains 

 tetraspores. 



The dichotomy of the branching of C. sitchensis is a com- 

 paratively late development in the growth of the stipe and is 

 not seen in the ojder parts. C. sitchensis is further described 

 as larger in all parts than C. rosa-niarina, though actual meas- 

 urements given do not accord with tliis. These /"acts suggest the 

 j^robability that the C. sitchensis of Postels and Ruprecht is the 

 late summer stage of C. rosa-marina. This supposition ex- 

 plains satisfactorily the absence of tetraspores in the one and of 

 dichotomy of the stipe in the other, the comparative lengths of 

 " internodes" and the difference in sizes of the two plants. 



The observations and impressions of subsequent writers add 

 additional weight to this view. In recounting the founding of 

 the genus by Postels and Ruprecht upon the Fucus rosa-marina 

 of Gmelin, Agardh (1. c. 185 1) observes of C. sitchensis " novo 

 consimili adjecta specie " (p. 294) and of C. rosa-marina " pras- 

 cedente (sitchensis) videtur proxima, cum nulla alia confun- 

 denda" (p. 296). 



Of the material collected by David Lyall at Vancouver island 

 "adrift on the beach at Victoria harbor" and reported as C. 

 sitchensis, although corresponding in size to C. sitchensis Har- 

 vey (1. c. 1862) remarks " perhaps this is only a luxuriant state 

 of C. rosa-marina." 



From these facts it would seem, therefore, highly probable 

 that C. sitchensis and C. rosa-marina are but different forms of 

 the same plant, and since the work of Schmitz has removed C. 

 reniformis to the genus Neurocaulon where also it is probable 

 that C. thiebauti should be classified, that Constantinea is a 

 monotypic genus, with Constantinea rosa-marina as the only 

 species. 



