944 EXPERIMENT STATION RECORD. 



of the cherry laurel were kept for some time under exactly similar conditions, and 

 the effect of temperature noted. The lowest temperature at which assimilation could 

 be detected was —6° C. , and this is said to be the first well-established case of assimila- 

 tion taking place at a temperature below 0° C. For temperatures between —6° C. and 

 33° C, it was found that assimilation is affected in the same way as is respiration. 

 If the illumination is sufficient the assimilation increases directly with the tempera- 

 ture. For temperatures above 33° C. the results are complicated by the injurious 

 effects of temperature, and the death of the leaves took place at 41 to 45° as was 

 shown by a rapid decrease in the respiration which ceases entirely after several hours. 



Influence of previous environment in variety tests, T. L. Lyon (Frur. Soc. 

 Prom. Afjr. Sri. 1902, pp. 70-7.3). — An account is given of a series of experiments with 

 Turkish red wiieat which was ol)tained from Ohio, Iowa, Kansas, and Nebraska and 

 grown at the Nebraska Station. Although this variety is supposed to be a fairly con- 

 stant one, wide differences are noted in the yield of grain and character of the plant 

 grown from the different lots. The author believes that the habits of growth of the 

 wheat plant are very readily changed by its environment and that a few years are 

 sufficient to produce a great difference in this respect. While certain variety charac- 

 teristics undergo slight changes others are deeply affected and reliable conclusions 

 can not be based ujion variety experiments in which the material is collected from 

 regions differing widely in their climatic conditions. 



The individuality of plants as a factor in nutrition studies, E. B. Yoorhees 

 and J. <i. Lip.MANS [I'roc Soc. J'rum. A(/7'. Sci 190;?, pp. 4---49). — Attention is called 

 to the importance of considering the individuality of the plant as a factor in plant 

 studies, especially when but a few individuals are under observation. Examples are 

 cited of pot experiments with several varieties of plants in which wide variations were 

 noted in the growth and yield of the different plants. The conditions of the experi- 

 ments were practically identical and the variation could be attributed only to the 

 individuality of the plants. The aim of the paper was to emphasize the particular 

 influence of plant individuality in plant nutrition studies so as to awaken suggestions 

 as to the best means for reducing sucli influences to a minimum. 



On the decomposition of proteid materials in plants, H. Karapetoff and 

 M. Sabachnikofp {Rev. Gen. Bot., 14 {1902), No. 167, pp. ^5--^6).— It having been 

 shown by several authors that the quantity of nondigestible proteid material in 

 plants depends upon the respiratory energy, the authors conducted a series of experi- 

 ments to investigate the effect of depriving plants of all sources of food to ascertain the 

 effect on the transformation of nondigestible proteids. Young seedlings of wheat 

 and barley were separated into equal lots, one of which was inunediately analyzed 

 and the other was kept in the dark for a considerable time, after which the plants 

 were analyzed by the same method as used for the analysis of the fresh ones. The 

 results of the experiments show that in the absence of nutrition tlie nondigestible 

 proteid material in jjlants had decomposed very slowly. For a few days there was 

 an increase, after Avhich a gradual diminution of the total proteids of the plants. 



The influence of wounds on the formation of proteid material in plants, 

 J. KovcHOFF {Hev. Gen. Bot., 14 {1902), No. 167, pp. 449-462). — Studies are reported 

 on the effect of cutting bulbs on the production of nondigestible proteids in plants. 

 Several varieties of onions were exj>erimented upon, the bulbs being cut in half, one 

 portion placed in a dark humid atmosj^here and the other analyzed at once. The 

 author found that wounding resulted in an increase in the nondigestible proteids. 

 This increased in a greater proportion than the total proteids. In the absence of 

 oxygen the nondigestible proteids made little or no increase when subjected to the 

 other conditions of the experiment. 



Investigations on vegetable oils and their formation, especially in the 

 olive, C. Hartwicii and W. Uhlmann {Arch. Pharm., 240 {1902), No. 6, pp. 471- 

 480). — The authors describe the microchemical reaction of various vegetable oils, 

 after which particular attention is given to the formation of oil in the fruit of the 



