578 SUMMARY OF CURRENT RESEARCHES RELATING TO 



•exsiccatae, and the distribution of each species throughout the world is 

 noted. A bibliography of Characea? and an index conclude the work. 



Characese from the Cape Peninsula.* — H. and J. Groves describe 

 a small collection of eight numbers, representing seven species, made by 

 Major Wolley-Dod on Table Mountain and the adjacent hills. Among 

 them are two of our common European species, Chara vulgaris and 

 C.fragilis, the rest being apparently endemic to Africa, and one being 

 a new species, C. Tanyglochis. The plants were very scarce. Since the 

 earlier half of the last century little has been done in collecting Characeae 

 in Cape Colony and Natal. The most interesting feature of the Chara 

 flora of Cape Colony is the presence of species intermediate between the 

 two sections Diplostichas and Triplostichas, which in other parts of the 

 world are fairly distinct. 



Polysiphonia violacea.t — S. Yamanouchi gives a brief preliminary 

 sketch of his cytological studies on Polysiphonia violacea G-rev., dividing 

 his notes into methods, germination of the carpospore and tetraspore, 

 spermatogenesis, oogenesis and fertilisation, tetraspore formation, and 

 abnormalities. He finds that the germinating carpospore contains forty 

 chromosomes, and the tetrasporic plant the same number : from which 

 he infers that the tetrasporic plants come from carpospores. The ger- 

 minating tetraspore contains twenty chromosomes, and the sexual plants 

 the same number, from which he infers that the sexual plants come from 

 tetraspores. The nuclei of the gametes contain each twenty chromo- 

 somes. The fusion nucleus has forty chromosomes, and gives rise to a 

 series of nuclei, some of which enter the carpospores. Tetraspore forma- 

 tion terminates the sporophytic phase with typical reduction phenomena, 

 so that the tetraspores are prepared to develop the gametophytic 

 generation. There is thus an alteration of sexual plants (gametophytes) 

 with tetrasporic plants (sporophytes) in the life-history of Polysiphonia, 

 and the cystocarp forms a part of the sporophytic phase. 



Spermatozoids of Fucacese.J — G. Retzius, who has been occupied 

 for some time on a study of the spermatozoids of the Evertebrata, has 

 now turned his attention to those of the Fucaceaa. He finds that, on 

 the whole, the spermatozoids of the lower animals and of Fucacese show 

 a remarkable similarity, but he is unable to say whether this extends 

 also to other groups of alga?. He finds in both the Fucaceas and in 

 many of the worms, molluscs, etc., a rosette of 4-5 spherules, which 

 constitute the body described by Guignard and others as the nucleus. 

 It does not lie within the body of the spermatozoid, but is outside it, 

 and belongs to the protoplasmic mantle. In front of the rosette of 

 spherules is the eye-spot, or chromatophore, which also lies outside the 

 pear-shaped body of the spermatozoid. The author then describes the 

 two cilia, of which the posterior one is always longer than, sometimes 

 twice as long as, the anterior one. The cilia are stout enough to be 

 examined in detail, and the author finds that both suddenly taper to a 

 fine point at their free end. This is also found among the lower 



* Journ. Linn. Soc. Bofc., xxxvii. (1906) pp. 285-7 (1 pi.). 



t Bot. Gazette, xli. (1906) pp. 425-3§. 



% Arkiv f. Botanik, v. (1906) No. 10, pp. 1-9 (figs, in text). 



