AGRICULTURAL BOTANY. 929 



The action of the alkaloids upon plants varies with the nature and strength 

 of the solution, but on the whole there is a general rise and intensification of 

 the vital processes, as seen in the increased transpiration and higher rate of 

 regeneration. The rate of regeneration after consecutive operations shows that 

 after the second operation there is a considerable decrease in the power of re- 

 generation and, conse(iuentl,v, a slowing down of the process, as well as a 

 lengthening of tlie period intervening between the operation and the first ap- 

 pearance of regenerated tissue. 



Studies on solanin from sprouts and flowers of the potato, A. Colombano 

 idaz: Chint. ItaL, 5,S {li)08). J, A'o. 1, pp. 19-37). — A study is reported on the 

 solanin occurring in tlie sprouts and flowers of the potato. The methods of 

 isolation and characteristics of the alkaloid are described, and comparisons 

 drawn between solanin obtained from the cultivated potato (Solanum tuher- 

 osiini ) and tliat isolated from S. sodomwum. 



The influence of aluminum salts on- protoplasm, M. Fluri (Flora. 99 

 (1908), Xo. 2, pp. 81-126). — Experiments with Spirogyra, Elodea. and Lemna 

 in cultures containing sulphate, nitrate, chlorate, and bichromate of aluminum, 

 yttrium nitrate, and lanthanium nitrate are described, .which showed that 

 there was a marked reduction of starch in plants grown in the light. While 

 these substances in nearly every instance checked assimilation, the assim- 

 ilatory processes were not wholly inhibited. These chemical compounds 

 seemed to exercise a kind of jjlasmolysis on the protoplasm without any con- 

 siderable contraction. 



The action is not believed to be a chemical one, as the amount of the 

 compounds present in the cells was very small. The aluminum salts appar- 

 ently act upon the diastases, which will account in some degree for the 

 reduction of starch. 



If grape sugar, glycerin, or isodulcite is added to cultures containing 

 aluminum compounds the injurious action of the chemical is inhibited. 



Effects of the rays of radium on plants, C. S. Gageb (Mem. N. Y. Bot. GarcL, 

 .', {1908), pp. TIII+278, pis. l-'i, flijs. IS). — After describing the discovery and 

 nature of radioactivity, a review is given of previous investigations on plants 

 and animals. From these investigations the conclusions are drawn that radium 

 rays and Roentgen rays modify the life processes of plants and animals, the 

 sensitiveness varying with the different species of plants and animals as well 

 as with the strength of the rays. The younger and especially the embryonic 

 tissues are more sensitive to the rays than the mature tissues, and with few 

 exceptions cell activities are retarded or completely inhibited. The evidence 

 for and against radiotropic response is conflicting, and internal changes appear 

 profoundly modified by the i)resence of chlorophyll in the cell. The activity 

 of enzyms is retarded by radium rays. 



The author carried on extensive exi)eriments with a number of species of 

 plants to determine the effect of radium rays on the growth of seeds, on 

 germination, synthesis of carbohydrates, respiration, alcoholic fermentation, 

 tropistic response, histology, nuclear division, etc. The exposure to radium 

 rays of lupine and buckwheat see<ls previously soaked in water resulted in 

 a retardation of growth, but an initial retardation of growth of white nni.stard 

 was followed by acceleration. The effect of exposure to radium rays varie<l 

 with the duration of exposure and the degree of activity of the radium. The 

 effect of radium acting through tlu' soil was to accelerate germination and 

 subsequent growth of unsoaked oats in proportion to the distance from the 

 radium, those plants farthest away being stimulated the most. The growth 

 of lupine shoots under like conditions was retarded, although the root growth 

 was 2 to 3 times as long as normal. Soaking seeds in water expose<l to 



