1020] AGRICULTURAL BOTANY. 481 



Plant growth, G. D. Buckner (Abs. in Science, n. ser., 52 {1920), No. 1SS2, 

 p. 44)- — A comparative study was made of the translocation of the ash, phos- 

 phorus, calcium, and magnesium from the cotyledons of germinaFTng garden 

 beans {I'hascohis vulgaris) when grown in distilled water culture and in garden 

 soil. In the distilled water culture 55 per cent of the original ash, 57 per cent 

 of the phosphorus, 25 per cent of the calcium, and 59 per cent of the magnesium 

 were translocated to the seedling. In seedlings grown in garden soil, the corre- 

 sponding iMjrcentages utilized l>y the seedling were 91, 92, 78, and 83. Attention 

 is called to the abnormal condition caused by the distilled water culture, and to 

 the fact that less calcium was removed from the cotyledons by the growing 

 seedling due to the insoluble form in the cotyledons and its structural function. 



Mineral constituents of the paired seeds of cocklebur, J. S. McHargue 

 (Ahs. in Science, n. ser., 52 {1920), No. 1332, p. Jf3). — Contrary to the opinion 

 of other investigators, the author found that, if well developed, both seeds would 

 germinate at approxi-iiately the same time if removed from the burs and planted 

 in moist sand. If allowed to remain in the burs, only one seed germinates until 

 the bur disintegrates and decays when the second seed will germinate. The 

 mineral constituents of the two seeds were found to be practically the same. 

 The large seeds averaged about 65 nig. in weight, the small seeds about 45 mg. 

 The large seeds are said to produce the largest seedlings. This is accounted for 

 by the fact that the large seed contains much more plant food than the small one. 



The ash of dune plants, W. D. Richardson {Science, n. ser., 51 {1920), 

 No. 1326, pp. 546-551). — The author has made a study of the ash of plants 

 grown on sand dunes of almost clear silicate near Gary and Michigan City, 

 Ind. The species investigated were the sand cherry {Prunus pumila), arte- 

 misia {Artemisia caudata), black oak {Qncrciis coccinea tinctoria), the three 

 gras.ses Calamovilfa, Ammophila, and Andropogon, and the scouring rush 

 {Equisetum hyemale intermedium). 



From the analyses it appears that dune plants obtain and concentrate in 

 their tissues the same mineral constituents commonly found in plants growing 

 on conmion soils, and these are accumulated in approximately the same relative 

 proportion. The author pays considerable attention to the I'ole of silicon in 

 the plants, and concludes that it is improbable that the plant organism woiild 

 absorb and store up such a substance, which could have no real use in its 

 life cycle. 



[Illumination and growth], V. Rivera (/ Problemi Agrari del Mczzoyiorno. 

 Rome: Mem. R. Staz. Fatal. Veg. Roma, 1919, pp. 18). — A preliminary study of 

 the effect of illumination, varied as regards duration and intensity, is consid- 

 ered as on the whole supporting the view that the accumulation of carbohydrate 

 is in relation to the number of hours during which the plant has the sunlight 

 and not to the intensity of illumination. 



The influence of light on some water plants, B. Sciiloss-Weill {Bat. 

 Centbl, Beihcftc, 35 {1917), 1. Aht., No. 1, pp. 1-59, figs. 22).— This is an ac- 

 count of the behavior of Ceratophyllum in darkness and the influence of 

 external factors, with explanations and comparisons with otiier water plants. 



Respiration, W. J. V. Osterhout {Abs. in Science, n. ser., 51 {1920), No. 

 1S2S, p. 596). — Attention is called to a simple method of measuring respira- 

 tion in plants, an account of which has already been given (E. S. R., 41, p. .524). 



Climatic control in relation to plant growth, W. E. Tottingiiam {Abs. in 

 Science, n. ser., 51 (1920). No. 1318, p. 352). — A brief description is given of a 

 small plant culture chamber for climatic control within a gi'eenhouse. 



Observations and interpretations regarding frost injury in West Prus- 

 sia in the winter of 191C-17, E. Wocke (Mitt. Deut. Dendrol. Gesell., 28 



