626 EXPERIMENT STATION RECORD. 



some algee, \. Aktari {-lahrb. ITm-. Bot. [Priiig.sheint], .'/.J (190G). Xo. 2, pp. 

 ni-2V,: ahs. in Bot. Cctithl., 102 (1906), No. 23, p. 5.95).— Experiments were 

 carried ou witli u nmulier of species of green algje in whicli the influence of 

 different concentrations of nutrients was studied. 



It was found tliat ammonium nitrate, which serA-ed as a source of nitrogen 

 for the algse, was witliout appreciable effect in solutions of 0.0.5 to 0.5 per 

 cent. Higher concentrations retarded growth, until at 5 per cent all growth 

 ceased. From the action of various salt solutions they were believed to have 

 other effects than those due to their osmotic activity. The nutritive value of 

 the different solutions of nitrogen varied somewhat, depending upon whether 

 or not glucose was present in the solution. The stimulating effect of the 

 glucose was apparent in strengths as low as 0.00.5 per cent, and it increased 

 to an optimum for the different species of alga* between 0.5 and 2 per cent. 

 The limit of concentration of the disaccharids was found to be almost double 

 that of the monosaccharids. 



The retarding effect of sodium chlorid was very evident even in the weakest 

 solution, and with an increase in strength of the solution the injurious effect 

 was quickly shown. Magnesium sulphate had only a slight retarding influence. 



Tannin cells of persimmons, B. J. Howard (Bui. Torreij Bot. Clvb. 33 

 (1906), No. 11, pp 567-576, figs. 8). — In a pi'evious publication an account is 

 given of the changes which take place in the tannin cells of persinnnons during 

 ripening (E. S. R.. 17. p. G13), and in the present paper the subject is discussed 

 at considerid)le length. 



The author has found that the tannin cells in the different species of per- 

 simmon examined differ materially in appearance and that the changes taking 

 place during the ripening process may be divided into three stages. 



In the green stage the tannin does not appear to be strongly localized, for 

 though it appears most abundantly in the loose parenchyma tissue where the 

 tannin cells are located, yet it is not limited to these cells nor even to the 

 region where the cells are most abundant. 



In the second stage of ripening radical changes occur in the physical and 

 possibly in the chemical constitution of the tannin. The tannin at this stage 

 is being or has l)een collected into the tannin cells, and the contents of these 

 cells become highly refractive. 



In the last stage the tannin masses have become highly refractive and the 

 addition of water causes little, if any. swelling. The contents of the cells are 

 friable, and pressure upon the cover slip results in the fracturing of the tannin 

 masses into irregular fragments. 



While the disappearance of the astringency and the development of mushi- 

 ness of the fruit are commonly associated, the author found that these fea- 

 tures do not run parallel, as it frequently occurs that mushiness develops 

 before the astringency is gone, while in other cases just the reverse is true. 

 This is the case particularly in specimens of Japanese persimmons cured by 

 the saki process. 



A study of beans yielding hydrocyanic acid, L. Guignard (Rev. Tit., 26 

 {1906), AO.S-. 655, pp. 5-9, pi. 1; 658, pp. 33-37; 658, pp. 89-95; 667, pp. 341-350, 

 figs. 9; 67. 'f, pp. 5J,3-5J,7 ; 675, pp. 573-576; 677, pp. 626-631: 678, pp. 663-667; 

 679, pp. 689-69-'i; 680, pp. 715-721).— \u historical, botanical, and chemical 

 study is given of Phaseolus lunatus, a number of the varieties of which have 

 poisonous properties due to hydrocyanic acid. A number of forms that have 

 been described as distinct species are by the author believed to lie varieties or 

 cultural forms of /'. lunutus. Those ])rinci])ally studied were the white and 

 colored .lava beans, Burma or white Indijin beans, Sieva beans. Cape beans, 

 which are extensively cultivated in Madagascar, and Lima beaus. These dif- 



