136 PHYSIOLOGY [Bot. Absts., Vol. V, 



964. Rumbold, Caroline. The injection of chemicals into chestnut trees. Amer. Jour. 

 Bot. 7 : 1-20. 7 fig. 1920. — Injection experiments were carried on in 1913 with 156 young Para- 

 gon chestnut trees grafted on native stock. Water, twenty-five inorganic substances (in- 

 cluding three colloidal metals), twenty-five organic substances (including extracts of normal 

 and of diseased bark), and five stains were injected. Various concentrations were used, and 

 the amount entering the tree was measured in each case. In general, solutions were absorbed 

 more readily than water, organic compounds more readily than inorganic ones and true solu- 

 tions more readily than colloidal ones. The more concentrated the solution, the more 

 rapidly it was absorbed. The rate of injection was most rapid in June and next in July, May, 

 August, September, October, and April, respectively. The rate was more variable in the 

 spring than in the summer or autumn, and was dependent to a considerable extent upon the 

 rate of transpiration. — Previous literature on plant injection is reviewed at some length. — 

 E. W. Sinnott. 



965. Rumbold, Caroline. Effect on chestnuts of substances injected into their trunks. 

 Amer. Jour. Bot. 7 : 45-56. 2 pi. 1920. — The author has injected a large number of substances 

 into Paragon chestnut trees, as reported previously (see entry next preceding). The present 

 paper describes the course of injected solutions in the tree, their effect on the tissues, and their 

 influence on the parasitic fungus Endothia parasitica. Solutions travel usually in last annual 

 ring of wood and were found to pass downward into the roots and upward into the leaves, 

 and in one case even into the fruit. They are confined to a path but little wider than the diam- 

 eter of the injection hole. The effect on the tree varied with the dilution of the solution and 

 with the season at which injection was made. Certain substances, notably water, the alkali 

 metals, colloidal metals, most organic compounds, certain dyes, and the water extract of 

 normal bark, were without noticeable effect on the tree. A few, particularly weaker dilutions 

 of alkali metals, apparently acted as slight stimulants. A third group, including the heavy 

 metals, water extract of blight canker, and some others, were detrimental, causing the death 

 of part or all of the tree. Particular solutions were often specific in their detrimental effects. 

 Results as to the effect of injected solutions upon the blight fungus were very inconclusive. 

 A little evidence is brought forward, however, which indicates that dilute solutions of lithium 

 salts injected in the spring months may check somewhat the growth of the fungus canker. — 

 E. W. Sinnott. 



966. Stoklasa, J., in collaboration with J. Sebor, W. ZdobnickT, F. Tymich, O. Horak, 

 A. Nemec, and J. Cwach. Influence of aluminum ions on seed germination. Sci. Amer. 

 Supplem. 87: 318-320. 1919. [Translated from Biochem. Zeitschr. 91: 137-223. fig. 1-15. 

 1918.] 



967. Wyeth, J. F. S. The effect of acids on the growth of Bacillus coli. Biochem. Jour. 

 12: 382-401. 1918. — Initial and final H-ion concentrations of Bacillus coli under varying con- 

 ditions are determined, and it is found that the final reaction of the culture solutions depends 

 on the initial H-ion concentration of the media, the buffer effect of the media, and the nature 

 of the acid. There is a critical point in the H-ion concentration beyond which growth is com- 

 pletely inhibited. — W. H. Chambers. 



ELECTRICITY AND MECHANICAL AGENTS 



968. Baines, A. E. Electrical conditions of the earth and atmosphere. Sci. Amer. 

 Supplem. 88: 290-291. 1919. — This article deals in part with plant life. The author believes 

 that everything growing in the soil is charged or electrified by the earth, — the roots, stems, 

 and veins being negative terminals, while the parts of the leaves between the veins act as 

 aerolae, taking their charge from the positive air. An ordinary electrical current passes 

 from air to earth and back again to air through the plant. If the soil is not moist to the root- 

 depth, or if it does not contain electrolytes other than water, the plant is deprived of its sup- 

 ply of current and must suffer injury. It is claimed that if about 1 per cent of ferro sulphate 



