198 SUMMAKY OF CURRENT RESEARCHES RELATING TO 



(2) the replacement of Floridean red by a green ; (3) the appearance of 

 the yellowish-brown pigment. The first is pathological ; the second is 

 chromatic adaptation ; the third is a pigment protecting the alga 

 against excess of light, and the author discusses the question as to 

 whether it is in the cell, in the cell-membrane, or in the surrounding 

 water. 



Effect of Alkaloids in Regeneration.* — S. Morgulis has made ex- 

 periments upon the scarlet runner bean in order to test the power of 

 alkaloids in hastening regeneration of wounded or removed organs. 

 The alkaloids used were a T -J 7 p.c, a toVtt P-c. and a T? ] w p.c. solu- 

 tion of each of the following, viz. sulphates of atropine, strychnine, 

 pilocarpine hydrochloride, and digitalin. The seedlings were placed in 

 suitable jars containing the solutions, and the stems were then removed. 

 With the exception of the stronger solutions of strychnine, the plants 

 were uninjured by concentrations which would have proved fatal to 

 animals. The effects produced varied with the strength and the nature 

 of the solutions, but there was a general increase in the rate and 

 intensification of the vital processes, especially that of transpiration. 

 Also the rate of regeneration is increased in relation to this quickening 

 of the various physiological processes. 



Effect of Gas upon Carnations. f — W. Crocker and L. I. Knight 

 have studied the effects of illuminating gas and of ethylene upon 

 flowering carnations, and find that the latter are very sensitive to traces 

 of the gas, young buds being killed by three days' exposure to 1 part in 

 40,000 parts of air. The injury is directly upon the flowers and is not 

 due to root-absorption. Ethylene is even more injurious, since a three 

 days' exposure to 1 part in 1,000,000 parts prevents the opening of 

 buds, and a twelve-hours' exposure to 1 part in 2,000,000 parts causes 

 open flowers to close. It is probable that the toxic effects produced by 

 illuminating gas are due to the ethylene which it contains. 



General. 



Function of the Male Cell in the Determination of Sex.| — C 

 Correns has made experiments with various plants of Plantago lanceolate/, 

 in order to determine the function of the male cell in relation to the sex 

 of the offspring. The author draws the following conclusions from the 

 results of his experiments. The formation of the offspring as regards 

 sexuality depends upon the character of the plant producing the egg- 

 cell and also upon that producing the pollen. The more pronounced 

 the female tendency of the germ-cells, so much the less is the effect 

 produced by the origin of the male cells. The influence of the pollen, 

 however, shows itself not only in the two extreme sexual forms but also 

 in the intermediate forms. On the whole it would appear that the 

 formation of the andrcecium and gyncecium of any particular stocks 

 and the sexual composition of the offspring of these stocks are not 

 always quite parallel. 



* Ohio Nat., ix. (1908) pp. 404-12 (5 figs.). 

 t Bot. Gaz., xlvi. (1908) pp. 259-76 (4 figs.). 

 X Bot. Gesell., xxvia. (1908) pp. 686-701. 



