BOTANY. 23 



In the experiments with sweet corn no influence of soil lias been noticed, but the 

 author believes that the climatic conditions have a marked influence, and that the 

 difference between stuck grown in the East and West is a result of climatic rather 



than of soil conditions. 



In the case of cucurbitaceous plants no variation due either to climate or soil was 

 ever noticed. 



In conclusion the author says: "Plants of different natural orders differ in the 

 degree to which influences of soil and climate are transmitted through the seed." 



Mutation in plants, D. T. MacDougal (Amer. Nat-., 37 (1903), No. 443, pp. 737- 

 770, figs. 10). — In this paper, which is No. 48 of the Contributions from the New 

 York Botanical Garden, the author gives a review of the work of l>e Vries on muta- 

 tion in plants, describing the various forms which have been developed from Oeno- 

 thera lamarckiana in the botanical garden at Amsterdam. The result of the writer's 

 investigations of a number of plants grown from seeds of these mutation forms are 

 described at considerable length, particular attention being paid to <3?. nanella and 

 (E. rubrinervis. Both of these are clearly separable from the parent and from each 

 other by physiological and taxononiic standards. These mutation derivatives are 

 found to be constant in their character, with no connecting or intergrading forms, 

 and their specific characters are borne out by their behavior when hybridized with 

 one another. 



The latent life of plants, R. A. Robertson ( Trans, and Proc. But. Sue Edin- 

 burgh, 22 (1902). pt. 2, pp. 178-191). — A discussion is given of the effect of gravity, 

 light and darkness, temperature, contact, injuries, chemicals, etc., on plant activity. 



Further experiments in plant breeding at the experimental farms, W. 

 Saunders I I'mr. and Trans. Roy. Soc. Canada, 2. ser., 8 (1902), IV, pp. 115-1:8. 

 figs. 6). — A record is given of plant breeding experiments carried on by the author. 

 in which the results obtained with cross-bred wheats, barleys, oats, peas, apples, and 

 gooseberries are given. 



Methods in plant physiology, II. S. Reed (Reprinted from Jour. Appl. .Views, 

 and Lab. Methods, 6(1903), Nos. 4-10, pp. 2267-2270, 2317-2320, 2386, 23S7, 2428-2430, 

 2464-2466, 2515-2517, 2569, 2570, figs. 11).— The author describes a number of simple 

 experiments in geotropism, heliotropism, and other plant motions. 



Experiments on peas in water culture, J. Golding (Centbl. Bakt. it. Par., 2. 

 Abt., 11 (1903), No. 1, pp. 1-7, figs. 4).— An account is given of water cultures 

 designed to investigate the process of the nitrogen fixation in the root tubercles of 

 peas, and especially to confirm the results of Nobbe and Hiltner (E. S. R., 12, p. 113). 



The peas were grown in nitrogen-free water cultures, receiving an otherwise com- 

 plete fertilizer. They were inoculated with water extract from crushed pea tubercles 

 so that plenty of organisms could be introduced to their roots. Duplicate cultures 

 were maintained and different series were provided. In one series the roots were as 

 far as possible covered with water; in the second air was excluded by covering the 

 surface of the water with oil; in the third the tubercles were exposed by raising them 

 out of the liquid, while in others the tubercles were covered and either air or oxygen 

 passed through the culture media. 



The growth of the different series is shown by figures ami described, the author 

 commenting upon the results. It was found that raising the roots out of the water 

 was an injurious process. The oil on the surface of the water prevented nitrogen 

 assimilation, and as there was also no access of oxygen the plants suffered. 



The results of the experiment seem to confirm those of Nobbe and Hiltner. Nitro- 

 gen assimilation took place only where the root tubercles were covered with water, 

 but even in this case the growth was much less than where the cultures were sup- 

 plied with combined nitrogen. In sand cultures the author has found the presence 

 of healthy tubercles on the roots to produce growth equal to or better than plants 



