1918] AGRICULTURAL BOTANY. 329 



functions as related to such substances as starch, oils, and coloring matters 

 are also discussed. 



A study of the fixation of the cytoplasm, A. Guilliekmond {Compt. Rend. 

 Acad. Sci. [Paris], 164 {1917), No. 11, pp. 6//S-647).— The author describes a 

 method which is claimed to produce as nearly perfect fixation of cytoplasm 

 as is possible to obtain. He states that in a drop of 3 per cent acetic acid the 

 mitochondria of epidermal cells of Tulip immediately assume a vesicular 

 appearance, while in one of 5 per cent strength the chondriome is almost en- 

 tirely dissolved at once. The mitochondria appear to be the least resistant of 

 the cellular elements, the most difficult of fixation, and particularly subject to 

 injury in osmotic changes. 



The presence of lipoids in Nicotiana as related to starch, and nicotin, A. 

 Parkozzani {Rend, e Mem. R. Accad. Sci., Let. ed Arti Zelanti Acireale, 3. ser., 

 7-8 {1912-1915), pp. 35-56). — A study of lipoids in young and in adult plants of 

 several species of Nicotiana is said to support the findings of Buscalioni (E. S. 

 R., 31, p. 427) in this respect, lipoids being often found in the chloroplasts of 

 the leaves of adult plants and being more abundant in the older basal leaves 

 than in those toward the apical regions, as also in the lower portions of the 

 stems. Lipoids are almost lacking in very young plants. Starch occurs in a 

 way somewhat paralleling the occurrence of lipoids as regards the stems and 

 the age of the plants, but it disappears from the marginal and some other 

 portions which, in leaves higher up, show a quantity greater than is usual. 

 Details are given of the relative abundance of these and other substances in 

 the various portions of the plant at different ages. 



Carbon [assimilation] in green plants, G. Pollacci {Atti 1st. Bot. R. JJniv. 

 Puvia, 2. ser., 17 {1917), pp. 29-51, figs. 2). — The studies previously noted 

 (E. S. R., 29, p. 28; 35, p. 435) having been continued with different plants, 

 the author observed an increase of weight in those from which atmospheric 

 air was excluded with the exception of the roots. It is concluded from this 

 that the roots of such plants are able to appropriate carbon dioxid from the 

 atmosphere and utilize it in their development. 



Report of the bacteriolog'ist, M. Mulvania {Tennessee Sta. Rpi. 1913, pp. 

 159-161). — This is a brief progress report on studies of the ability of bacteria 

 to produce humus from definite forms of organic matter, such as cottonseed 

 meal, ground straw, and cow dung, and of the influence of humus on nitro- 

 gen-assimilating bacteria (Azotobacter), employing certain modifications of 

 methods previously described (E. S. R., 28, p. 727). 



Humification was found to proceed in direct proportion to the amount of 

 organic matter present, but the sterilized flasks always gave as much humus 

 as those inoculated with bacteria and often "more. Sterilization slightly de- 

 creased the extractable matter. There was a decided loss of nitrogen from 

 the inoculated flasks. It was concluded that " under the conditions main- 

 tained organic matter in the inoculated flasks is decomposed, nitrogen is lib- 

 erated, but humus is not produced." 



Present methods are not deemed adequate for a study of the effect of humus 

 upon nitrogen assimiliation by Azotobacter. The associative action of Azo- 

 tobacter, Bacilhis radicicola, and B. subtilis in nitrogen fixation was observed 

 to add more nitrogen to the mannite solution than when these microorganisms 

 worked in any other combination. 



The influence of water and of mineral matters on tlie development of plant- 

 lets, L. Maquenne and E. Demoussy {Compt. Rend. Acad. Sci. [Paris], 164 

 {1917), No. 26, pp. 979-985). — The lowering of the growth rate of pea seedlings 

 when sprouted in the purest water obtainable is thought to result from the 

 absence of the very minute quantities of material commonly dissolved out of 



