20 EXPERIMENT STATION RECORD. 



Cotyledons were planted with a small piece of epicotyl left attached, and it was 

 found that the whole plant was regenerated. This took place whether a whole 

 cotyledon or only a piece of the cotyledon was left intact, indicating that regeneration 

 is not wholly dependent on the food supply. When the epicotyl was injured or 

 removed, buds which had been produced in normal growth developed, and upon the 

 removal of these other shoots continued to appear until all the embryonic tissue 

 was dead. After the epicotyl had attained a height of about 10 cm., regeneration 

 became uncertain, and at 20 cm. only an occasional seedling was able to regenerate 

 mutilated portions, even though the cotyledons were found to be rich in food 

 supplies. 



The author concludes that regeneration of the epicotyls of beans and peas is 

 dependent more upon the age of the tissue than upon the amount of food supply at 

 hand. 



On different degrees of availability of plant nutrients, 0. Loew and K. Aso 

 (Bui. Col. Agr., Tokyo Imp. Univ., 6 (1905), No. 4, pp. 335-346) .—The results of 

 studies on the chemical availability of lime and magnesia are given, from which the 

 authors claim that the former ratio of lime to magnesia, or the lime factor as it was 

 called (E. S. R., 15, p. 1062), was based on the idea of an equal state of availability 

 of the lime and magnesia present in the soil. 



It has since been learned that the ratio changes with the availability of the bases, 

 and magnesia in the burnt form is more available than in the pulverized magnesite. 

 The magnesium sulphate is still more available than either. The physiological action 

 of lime and magnesia must be distinguished from the changes which these bases 

 exert upon the soil. Gypsum acts indifferently on account of its low availability. 

 The carbonate of lime is much more available for plant use. 



Can aluminum salts increase plant growth? Y. Yamano (Bui. Col. Agr., 

 Tokyo Imp. Univ., 6 (1905), No. 4, pp. 429-432). — Experiments are reported with 

 barley and flax grown with and without various amounts of ammonium alum, from 

 which it appears that this salt exerts a stimulating effect when used in moderate 

 quantities. 



The action of poison on plants, E. Yersciiaffelt (K. Akad. Wetensch. Amster- 

 dam, Proc. Sect. Sci., 6 (1904), pt. 2, pp. 703-707, dgm. 1).— The author claims that 

 the ability to absorb water through the osmotic properties of the protoplasm will 

 continue until the cell walls allow no further expansion or the plant is killed. 



When any part of an organ is previously killed no water is absorbed. On the 

 contrary the dissolved substances in the cell sap are diffused out. This fact the 

 author makes use of as a basis for determining the action of poisons on plants, and 

 reports upon investigations with portions of potato tubers, beet roots, leaves of aloes, 

 and leaf stalks of the begonia and other plants. A piece of tissue was considered 

 undamaged if after having stayed in the poisonous solution for 24 hours and then in 

 water for 48 hours it continued to gain in weight. 



The effect of a number of substances on portions of plants is shown, indicating the 

 harmful limit of concentration. This was determined for copper sulphate at between 

 0.002 and 0.003 grammolecule per liter. It was found also that the harmful limit of 

 concentration may be determined for neutral mineral salts which in certain dilutions 

 are not injurious. Sodium chlorid was found to partially neutralize the poisonous 

 effect of a number of organic poisons, such as oxalic acid, chinine hydrochlorid, etc. 



Concerning- cauliflorous flowers and fruits, L. Bfscalioni ( Malpighia, 18 (1904), 

 pp. 50, pis. 2; abs. in Bot. Centbl., 96 (1904), No. 49, pp. 578, 579). — A critical review is 

 given of observations and theories regarding the direct occurrence of flowers and fruits 

 on the trunks and larger branches of trees, such as cacao, calabash, and other tropical 

 trees. 



The author believes the production of flowers and fruit in this manner to be a primi- 

 tive characteristic which persists in many plants that live in moist, hot regions. The 



