Algae. 443 



weeks time sexual plants with ripe antheridia and carpospores, and 

 tetrasporic plants with mature spores. The tetrasporic plants are 

 always more abundant, as well as on an average larger than sexual 

 plants. After a few remarks on the methods of fixing employed in 

 his work, the author describes fully the vegetative characters of 

 the thallus, with special regard to the nuclei; and he compares these 

 bodies with those of Polysiphonia and Nemalion, the nuclei of which 

 have been carefully studied. Two methods of cell-division are de- 

 scribed : the nuclei appear to have no part in the process. Branched 

 hairs are frequently borne on the upper borders of the younger cells 

 the function of which is unknown ; they probably perform the func- 

 tions of absorbtion and respiration. Sexual and asexual reproduction 

 are very fully discussed, especially with regard to nuclear division, 

 and the behaviour of the tetraspore mother-cells is compared in 

 tabular form with those of Corallina and Polysiphonia. One point 

 is emphasized by this comparison : namely, that at a critical stage 

 in the history of rather closely related members {Polysiphonia and 

 Griffithsia) of a highly specialized group, the phenomena are of a 

 most varied nature. During the period of synapsis, and up to the 

 time of the forma tion of the chromosomes, the cytological events in 

 Polysiphonia are more like those in Lilium than those in Griffithsia 

 or Corallina. From this and other facts, the author concludes that 

 cytological phenomena cannot be considered trustworthy guides to 

 relationship. 



The others points dealt with are: Tetraspore-like structures on 

 sexual plants, Vegetative multiplication, and Germination of spores. 



In a final discussion of results, the author states that 1. There 

 is in Griffithsia an antithetic alternation of generations, the game- 

 tophyte being represented by the sexual plants, the sporophyte by 

 the sporogenous cells of the cystocarp. 2. In addition to this, there 

 is a regulär succession of tetrasporic individuals and sexual indivi- 

 duals. The tetrasporic individuals resemble the sporophyte in num- 

 ber of chromosomes; they resemble the gametophyte in morphological 

 differentation. They are to be considered as a phase of an homo- 

 logous alternation of generations, not the equivalent, wholly or in 

 part, of the sporophyte of Archegoniates. E. S. Gepp. 



Lucas, A. H. S., Revised List ofthe Fucoideae and Florideae 

 of Auslralia. (Proc. ofthe Linn. Soc. New South Wales. XXXIV. 

 1. 1909. p. 9—60.) 



This list forms part of the Presidential address delivered by the 

 author. After a short sketch of the work by previous writers, he 

 gives a list of 1050 species of the Fucoideae and Florideae, merely 

 indicating whether they occur on the north, south, east or west 

 coasts. Harvey's names, where altered, are given as sjmonyms. 

 The list is invaluable to anyone working at the marine flora of 

 Australia. E. S. Gepp. 



Philip, R. H., Interesting diatom near Hüll. (Naturalist. 634. 

 November 1909. p. 376—377.) 



The diatom in question is Amphiprora constricta Ehr. (=s= Stau 

 ronella constricta Mer.), which was originally recorded from Marfleet 

 near Hüll, and has now been once more found there, by the author 

 of this note. It was in great abundance and pure of any mixture 



