72l> SUMMARY OF CURRENT RESEARCHES RELATING TO 



under clear glass, after 48 hours, they bend over towards the light. 

 The same result was obtained with yellow arlass, though the effect was 



t o o 



more delayed. In a red light the filaments become oblique about the 

 third day, then lower themselves to the substratum, where they creep 

 along the surface. With other colours, green, blue, or violet, they 

 become horizontal, but do not bend downwards. The number and size 

 of the sporangia were also affected by different coloured lights, the 

 yellow being the most favourable to the development of the fungus. 



CRYPTOGAMS. 



Pteridophyta. 

 (By A. Gepp, M.A. P.L.S.) 



Cytology of Reproduction in Nephrodium.* — S. Yamanouchi has 

 studied Nephrodium molle "in order to understand the characteristics 

 of the nuclear behaviour of the species." The present work is intro- 

 ductory to a study of apogamy, and hence special attention is given to 

 the chromosomes. The author disagrees with Farmer and Digby, and 

 is of the opinion that there is a constant number of chromosomes in 

 N. molle in the sporophyte generation, and also that there is reduction 

 of the chromosomes in the normal life-history. 



In a second paper j the author publishes his results in connection 

 with the spermatogenesis, oogenesis, and fertilisation. Two important 

 points are made out in the present account, viz. that it is possible to 

 count the chromosomes in the gametophyte, and that the number of 

 chromosomes is constant, being about sixty-four or sixty-six. 



In a third paper f he publishes his latest conclusions with respect 

 to apogamy in this plant. The author is of the opinion that the nuclear 

 condition in the normal life-cycle favours the antithetic theory of the 

 alternation of generations. Apogamy appears to be abnormal, but tends 

 to show that the number of chromosomes is not the only factor serving 

 to determine the characters of the sporophyte and gametophyte. N. 

 molle presents the first instance known among plants where the sporo- 

 phyte generation possesses the haploid number of chromosomes. 



Origin of Ulodendron Impressions of Bothrodendron.§ — A. Eenier 

 contributes a note upon the Ulodendron impressions of B. punctatum. 

 The author has studied a new specimen recently accptired by the 

 University of Liege, and finds that the view put forward by Watson as 

 to the branch origin of the scars is perfectly correct with regard to 

 B. punctatum, and in the absence of further evidence it is reasonable to 

 suppose that similar scars on Ulodendron and Lepidodendron may have 

 had a similar origin. 



Leaf-trace in Gyropteris and Tubicaulis.|| — P. Bertrand, after a 

 careful study of Gyropteris and Tabkmdis, concludes that these two 

 genera belong to the Zygopteridese. The author believes that Gyropteris 

 may have been derived from the genus Diplolabis by loss of the plan of 



* Bot. Gaz.,xlv. (1908) pp. 1-30 (4 pis.). f Tom. cit., pp. 145-75 (3 pis.). 



\ Tom. cit., pp. 289-318 (2 pis. and 3 figs.). 



§ Comptes Rendus, cxlvi. (1908) pp. 1428-30. || Tom. cit., pp. 208-10. 



