304 THE JOURNAL OF BOTANY 



tlon of a complex life-cycle, thus squeezed into an academic two-phase 

 scheme ^. 



V. Also within the present generation, the Florideae share in the 

 new outlook on the science which has been opened up under the 

 heading of CEcology =^ (Warming, 1896). This special line of 

 investigation is designed to replace the rule-of- thumb methods of the 

 older school of naturalists, and to analyze and tabulate the enormous 

 amount of ' general information ' acquired subconsciously by the 

 older ' collector,' which largely constituted the charm of out-door 

 investigations. 



The difficulties of the problems presented by the Florideae are 

 enormous, and can be only overcome b}^ long-continued and careful 

 work ; the main held of research being invisible to the human eye, 

 submarine, beyond the reach of either direct observation or experi- 

 ment, and only to be explored by dredging and the use of deep-sea 

 instruments — often on dangerous rocky ground — at all seasons of the 

 year. The vegetation of the tide-range inevitably receives at first an 

 exaggerated amount of attention : all such vegetation is of a depaupe- 

 rated character, and by no means representative of the main sti-ength 

 of the inventive genius of the group. The same applies with even 

 greater force to the reduced and hardy relics characteristic of the 

 more extreme positions in zones above the high-tide mark, the case 

 of dark caves, the vegetation of the salt-marsh, brackish water, and 

 extension into freshwater streams and ditches. Owing to their more 

 ready accessibihty, and their association with more interesting types 

 of land-vegetation, these depauperated wastrels of the sea are in 

 danger of being given a degree of prominence out of all proportion 

 to their essential value, either morphologically or phylogenetically. 

 The true vegetation of the sea is in the sea, and may be said to begin 

 at low-tide level. 



BAIIBAIIEA EIVULARIS IN BRITAIN. 



Br A. B. Jackson, A.L.S., and A. J. Wilmott, F.L.S. 



At first sight it Avould appear from Mr, Marshall's account of 

 this plant (auf(\ p. 211), that we have an addition to our Britisli 

 species of Barbarea, but in realit}'- it is nothing of the kind. 

 Mr. Marsliall seems to have forgotten the paper on Barharea vul- 

 f/aris (Journ. Bot. lOlG, 202), in which B. rivularis Martr. Don. 

 has been fully dealt Avith jind shown to be merely a synon^'m of 

 B. vul<)aris var. silvestris Fr. It is a form not uncommon in 

 Britain, and we have now seen it from at least a dozen vice-counties 

 as well as from Ireland. Tlie British examples are not of the short- 



1 Yamanouchi (190G), loc. cit. p. 433 : Bower (1919), The Living Plant, p. 482 : 

 cf. Cleland (1919), Annals Bot. p. 347 for the prevailing dogma — " the cystocarp 

 of Nemalioii is not sporophytic in character, and there is no cytological alterna- 

 tion of generations." 



2 Warming (1909), Ecology of Plants, Eng. edit. p. 170. Br.rgesen (1903), 

 Botany of the Faeroes, p. 339 ; (1908) p. 683. Cotton (1912), " Clare Island Survey," 

 Proc. Roy. Irish Acad. 31. 



