BOTANY. 1047 



tliis fact the author coiicki(ies that the stigmas of phmts secrete sul)stances which 

 favor the germination of the pollen of related species and prevent that of very dis- 

 simihir ones. 



Canadian experiments with Nitragin for promoting the growth of legumes, 

 F. T. Shutt and A. T. Charron {Proc. and Tram. Roy. Soc. Canada, 2. s:r., 6 {1900), 

 Sec. Ill, pp. 55-70, ph. 2). — A brief review is given of the subject of nitrogen assimi- 

 lation by leguminous plants, and the efforts that have been made in the preparation 

 of pure cultures of the nitrogen-assimilating organisms are described. Tlie authors 

 conducted a series of experiments at the experimental farm, Ottawa, with Nitragin, 

 using a prejiaration for clover, horse beans, alfalfa, vetches, and peas. The results 

 with clover, peas, and horse beans are described at considerable length. The experi- 

 ments, with the exception of the horse beans, were on the whole satisfactory and 

 furnished evidence as to the value of this inoculating material. The experiments 

 w ith clover and peas invariably gave higher yields for treated plats when compared 

 with those grown in similar soils and under like conditions except as to inoculation. 

 Tlie vitality of the bacteria in the culture medium is the most serious detriment to 

 its use. These organisms are particularly susceptible to temperatures above 100° F. 

 as well as to strong light, and their vitality can not be guaranteed for more than 

 a))Out (5 weeks from the time of preparation. For this reason it is considered <k)ubtful 

 whether the use of Nitragin will ever come into general practice by farmers. 



Photosynthesis without living plants, L. M.xccitiati {llcv. Gen. Bol., 15 {190.3), 

 Xo. lfJ:>, })p. 20-25, Jigx. 2). — The autlior briefly reviews the published results of a 

 number of investigators on the i)Ossibility of enzyms being concerned in photosyn- 

 thesis, after which he describes experiments which seem to indicate that these fer- 

 ments have an important bearing upon the subject of photosynthesis. After carefully 

 washing leaves in distilled water, a glycerin extract was made which when shaken 

 with benzin gave an amorphous, flocculent precipitate, recognized as the enzym 

 l)resent in the leaves. At the same time the leaves w^ere washed, and after drying 

 for 3 hours at a temperature of 100° C. were finely powdered, and part of the powder 

 was again extracted with glycerin. This yielded an enzym similar to that taken 

 from the living leaves. Both the enzyms and the dried, powdered leaves were sub- 

 jected to experiments to demonstrate their ability to carry on photosynthesis. As a 

 result of numerous experiments the author found that the glycerin extract alone was 

 unable to accomiilish any photosynthesis, but the powdered leaves containing the 

 enzym, either alone or when the glycerin extract was added to them, Avere able to 

 liberate oxygen forming formaldehyde. These experiments, the author believes, 

 indicate that photosynthesis is due to the presence of a soluble ferment and the 

 chlorophyll acts simply as a chemical screen or a sensibilizer. 



A preliminary account of this investigation is given in <'om]d. Until. Arad. Sri. 

 Paris, 135 {1902), No. 24, pp. 1128, 1129. 



Methods in plant physiology, H. S. Heed {Jour. Apjd. Micros, and Lab. Methods, 

 5 {1002), Xox. 10, pp. 2004-2000; 11, pp. 2045-2048; 12, pp. 2084, 2085; 6{190S), Xos. 

 1, pp. 2127-2129; 2, pp. 2174-2176; S, ]>/>. 2231-2234, fif/x. 10) .—The author gives 

 directions for a number of experiments in lal)oratory investigations on plant nutri- 

 tion, osmosis, transpiration, photosynthesis, enzyms, etc\ 



Phyllobiology, A. Hansgirc^ {Phi/Uohiologie. Leipzig: Borrdraet/er Bros., 1903, 

 [ip. XIV-]r486, figK. 40). — In this volume the author gives the results of many years' 

 observations on the biological phenomena which are associated with leaves of 

 deciduous plants. The special modifications and adaptations of tlie leaves of 61 

 families of plants are described, and their grouping according to ecological types 

 is discussed. The various protective adaptations of young leaves, leaves of seedlings, 

 etc., are treated in a separate chapter. 



Reports of Danish experiment stations for plant culture during 1900 and 

 1901 {Tidsskr. Landhr. Planteavl, 8 {1902), pp. 194-222; 9 {1902), pp. 141-164).— 



