518 SUMMARY OF CURRENT RESEARCHES RELATING TO 



decreases, but rapidly increases when assimilation begins. When branches 

 were kept in the dark the new shoots were found to contain more than 

 7 p.c. of the glucoside, but the amount diminished as the shoots grew. 

 Salicin is found in young leaves developing normally ; it disappears for 

 a short time and then reappears. Separated leaves lost 30 p.c. of 

 salicin during the night, but recovered the amount in the daytime. In 

 the case of attached leaves it was found that with the loss of salicin in 

 the leaves during the night there was a gain in amount contained in 

 the bark. These changes in the amount of salicin are accompanied by 

 inverse changes in the amount of the catechol. The author concludes 

 that the decomposition of salicin occurs in every cell, the dextrose 

 migrating towards the green parts, whilst catechol remains in the cell 

 and combines with dextrose coming from cells situated nearer to the 

 bark, to re-form salicin. The amount of catechol corresponds with the 

 decrease in the absolute quantity of salicin. 



Production of Alcohol in Seeds.* — T. Takahasi finds that sterilised 

 peas (33 grm. weight) kept in water for 38 days, produced much carbon 

 dioxide and nearly 1 grm. of ethyl-alcohol. Many of the peas retained 

 the power of germinating. The production of alcohol was due to the 

 protoplasm as control experiments showed that zymase was absent. 



Action of Uranium on Plants.f — 0. Loew finds that dilute solu- 

 tions (*01 p.c.) of uranium nitrate increase the yields of peas and oats, 

 stimulating the production both of straw and seed. Solutions con- 

 taining '2 p.c. of the salt proved fatal to young pea-plants in three 

 days. 



Action of Sodium Fluoride and Potassium Iodide and Potassium 

 Ferrocyanide on Plants. — K. Aso t finds that solutions containing 

 •05 p.c. of sodium fluoride have a more or less injurious effect on the 

 germinating power of seeds. Growth of shoots of barley and rice was 

 stimulated by solutions containing *001 p.c. of the salt, but wheat 

 shoots were injured. Peas grown in soil were stimulated by small 

 amounts of the same salt (*001 grm.). 



S. Suzuki § finds that dilute solutions of potassium iodide ('006 

 grm. in 2-3 kilos of soil) increased the growth of peas, both as regard 

 straw and seed. Potassium ferrocyanide in solutions containing only 

 •0001 p.c. gradually destroyed barley plants. 



General. 



Poppies and Insect Visitors. || — F. Plateau has made further ex- 

 periments on the visits of insects to flowers of Papaver orientate from 

 which the petals have been removed. He finds that in such flowers 

 fewer seeds are produced than in normal flowers. This, however, is not 

 due to a diminution in the number of insect visitors in the case of the 



* Bull. Coll. Agric Tokio Imp. Univ., v. (1902) pp. 243-6. See also Journ. 

 Chem. Soc, torn, cit., p. 170. 



t Tom. cit., pp. 173-5. See also Journ. Chem. Soc, torn, cit., p. 173. 



X Tom. cit., pp. 187-05. See Journ. Chem. Soc, loc cit. 



§ Tom. cit., pp. 199-201 and 203-5. See Journ. Chem. Soc, loc. cit., p. 174. 



|| Bull. CI. Sci. Acad. Boy. Belg., 1902, pp. 657-84 (4 figs, in text). 





