BOTANY. 13 



(luring this time there was any noticeable decomposition of reserve protein. The 

 juice of portions of the trunk was prepared for examination liy methods which are 

 described in detail. The results showed that neither asparagin, tyrosin, or leucin 

 were present; hence that in the period of rest no decomposition of protein takes 

 place in the juice of the plant. 



The poisonous action of quinone, T. Furut.v {Bui. Col. Agr. Imp. Unifv. Tokyo, 

 4 {1902), No. 5, pp. 407-410). — While many of the phenol derivatives have been 

 tested for their poisonous properties, quinone seems to have been wholly neglected. 

 According to Beijerinck, this substance is produced by the action of a soil fungus 

 {StreptothrLv chromogena) on certain proteids. The author has conducted a series of 

 experiments with this substance to ascertain whether it is a general poison, his 

 experiments being made with shoots, twigs, leaves, various algte and fungi, bacteria, 

 insects, tadpoles, and mice. The different experiments are briefly outlined, and 

 from the results obtained it is concluded that quinone is a strong poison, stronger 

 indeed than the other closely related benzin derivatives. As a result of his investi- 

 gations the author thinks there is little basis for the hypothesis of Beijerinck that 

 the relatively large amount of humus in the soil is due to the action of quinone. 

 He believes that if quinone is i^roduced by the soil fungus it must be changed as soon 

 as formed, for otherwise animal and vegetable life in the soil woul<l be destroyed. 



Are caflfein and antipyrin in high dilutions poisonous to plants ? S. Sawa 

 {Bui. Col. Agr. Imp. Univ. Tokyo, 4 {190:2), No. 5, pp. 411, 412).—'Y\\q author carried 

 on experiments with onion plants to determine the poisonous action of these alka- 

 loids in high dilution. The plants remained alive for nearly four weeks in a solution 

 containing 1 part of the alkaloids to 1,000 of the nutrient solution. The caffein 

 gradually proved to be more injurious than the antipyrin. In the second experiment 

 in which young celery jjlants were used the amount of the bases added to the solu- 

 tion was 0.1 and 0.25 per cent, respectively. In about 2 weeks the injurious action 

 of the alkaloids was observe<l, commencing with the wilting of the leaves. The 

 injurious effect of caffein in this high dilution appears remarkable since the epi<;ler- 

 mis of tea leaves is comparatively rich in it and remains uninjured. It is believed 

 that the caffein here jiresent is localized in the vacuoles and surrounded by such a 

 density of cytoplasm as to protect the cell against injury. 



Has urea any poisonous action on phsenogams ? S. Sawa {Bui. Col. Agr. Imp. 

 Univ. Tokyo, 4 [1902), No. 5, pp. 413, 414)- — As urine is sometimes applied as a manure 

 before its urea is completely split up by bacterial action into ammonia and carbonic 

 acid, the autlior has investigated the poisonous action of urea toward pha^nogams. 

 Four plants were placed in a Knoji's solution, two receiving an addition of 0.5 to 0.001 

 of urea. These plants were allowed to remain for 5 weeks in the solution, which was 

 twice renewed during that time. They l)egan the formation of flowers, but only one 

 of those to which urea had been applied made a full flower development. The new 

 branches developed by the 4 plants were much more vigorous on those plants grown 

 in the control solutions than those which had received urea. The leaves began 

 dj-ing and at the expiration of 5 weeks the plants were measured. This showed the 

 injurious action plainly, the control plants having made more than twice the growth 

 of the others. 



The poisonous action of potassium persulphate on plants, S. Sawa {Bui. Col. 

 Agr. Imp. Uiiir. Tokyo, 4 {1902), No. 5, pp. 4I0, 41G)- — Experiments are reported in 

 which a 0.5 per cent solution of potassium jjersulphate was applied to certain algae 

 and diatoms, all of which died within 1 hour. Branches of rape .plants in the same 

 solution showed an injurious effect within 24 hours. An injurious effect of the same 

 substance when still further diluted was shown on plum branches, the buds being 

 entirely killed withm 10 days. Onion plants were more resistant, showing the effects 

 of the chemical on the tips of the leaves after 10 days, at which time growth seemed 

 to stop. 



