606 SUMMARY OF CURRENT RESEARCHES RELATING TO 



beyond a very slight shrinkage of the cell. The other species referred 

 to is a doubtful form of Chlamydomonas, the most prominent charac- 

 teristic of which is a distinct, well-marked channel running up through 

 the transparent " beak " (" Hautwatz "). The two cilia are not easy to 

 see, even after staining. 



New Siphoneous Alg-a.* — A. and E. S. Gepp publish a diagnosis 

 of a new species of Udotea, U. verticillosa, which occurs in the West 

 Indies and is most nearly allied to U. aryentea. It was collected by the 

 ' Challenger ' Expedition. 



Fucus spiralis. f — F. Borgesen deals very fully with the question of 

 nomenclature regarding Fucus spiralis L. and F. platycarpus Thuret. 

 Professor Sauvageau takes the view that F. spiralis was not sufficiently 

 defined by Linnasus, and that it included a form of F. vesiculosus, viz. 

 f. spltserocarpa. Borgesen, on the other hand, takes the view that the 

 original diagnosis of Linnaeus is quite clear, and refers to it the plant 

 later named F. platycarpus by Thuret. He further states that the dif- 

 ferences which induced Thuret to regard his plants as constituting a 

 new species are really nothing but modifications according to the 

 latitude in which F. spiralis grows. Even among his Faeroese material 

 he finds occasional plants or portions of plants, which remind him 

 strongly of F. platycarpus ; and his opinion is that Thuret's F. platy- 

 carpus is a more southerly variety of F. sjnralis, while the typical form 

 occurs more particularly in the northern regions, but may also be found 

 growing together with var. jilatycarpa in the southern. This opinion he 

 states in his Botany of the Faeroes, and he has seen no reason to depart 

 from it since. The views, therefore, of Borgesen and Sauvageau are 

 opposed, since Borgesen considers the species is F. spiralis with var. 

 typica Borgs. (= f. typica Borgs.), with f. limitanea Mont. (= f. nana 

 Kjellm. (Borgs.), and var. platycarpa Thur. (Borgs.), while Sauvageau 

 thinks that the species is F. platycarpus Thur., with var. spiralis Sauvag. 

 The author goes on to describe the specimens of F. spiralis in Herb. 

 Linne, and these are also represented in photographs. As to the dif- 

 ferences which distinguish F. spiralis and F. in flatus, the author finds 

 that, though the species may be confused in herbaria, they are easily 

 recognised in the open, as F. inflatus grows on sheltered coasts at about 

 low-water mark, while F. spiralis L. occurs at about high-water mark. 

 Finally, the views of other authors, both old and modern, are discussed. 



Zoning of Brown Seaweeds.! — S. M. Baker discusses the causes of 

 the zoning of brown alga? on the seashore. In order to have a clear 

 understanding of the conditions under which the alga3 were growing at 

 a particular locality (near Bembridge, in the Isle of Wight), the author 

 took a set of measurements to find their vertical distribution in relation 

 to the tides. The methods of work are described, and a table is given 

 showing the upper and lower limits, and the mean readings of five 

 species and of the Laminarias. Three phases of the life-history of 



* Journ. of Bot., xlvii. (1909) pp. 268-9. 



t Journ. Linn. Soc. Bot., xxxix. (1909) pp. 105-19 (1 pi. and figs, in text). 



j New Phytologist, viii. (1909) pp. 196-202 (diagram and figs.) 



