AGRICULTURAL BOTANY, 723 



the soil for seriiiination. The results sliowed that with the heated soil there 

 was a decided retardation of geriuination. This is attrihutetl to the fact that 

 the heating of the soil had delayed germination by a (h'creased rate of inihibi- 

 tion. which in tnrn was due to the increased osmotic activity of the soil solution 

 caused by the organic matter of the soil being renden^l soluble in the process 

 of heating. 



On the effects of injuring the cotyledons on the growth of the seedlings, 

 Helene Jacoiu {Flora, 101 {Id 10), Ao. 2, 27!)-28<), figs. ^).— The results are 

 given of experiments on Phaseolufi multiflorus, Cucurhita pepo, Picea excelsa, 

 and Piinis .si/lrmtris. in which portions of the cotyledons were removed and the 

 subsequent growth of the plants in fluid and pot cultures in both light and dark- 

 ness was observed. It was found that a reduction of the reserve food of the 

 cotyledons produced an acceleration of the growth of the seedlings in the earlier 

 stages of their development. The acceleration, however, varied according to 

 the individual plants and the different growth conditions. 



On the metabolic changes due to geotropic stimulation, V. Grafe and 

 K. LiNSBAUEB {Sltzbcr. K. Akad. Wlss. [Vienna], Math. Xatuiw. A7., 118 {1900), 

 I, Xn. 7, pp. 907-916). — As the result of experiments with the root tips of Lupiniis 

 alhiif; and Ticia faba, the authors could not ascertain any constant difference in 

 the reducing substance between the stimulated and the nonstinmlated roots. 

 The absolute (piantity of reducing substances from the root tip was at a mini- 

 mum and much below the values fonn<l by Czapek. 



On the excretion of roots, Brocq-Rousseu and E. Gain {Compt. Rend. Acad. 

 Set. [Paris], 150 {1910). No. 2',, pp. 1610, 1611).— As the result of experiments 

 with roots of bean seedlings, the author claims that during the first period of 

 growth peroxidase is excreted by the root hairs, and that the general hypothesis 

 of osmotic excretion by root hairs has been verified experimentally. 



Influence of light on the development of fruits and seeds of higher plants, 

 W. LuRiMENKo {Rev. Gen. Bot., 22 {1910). No. 2-')6. pp. l'/5-17.'), figs. J).— A 

 study has been made of the effect of confined air within the pericarp of fruits 

 and of light on the development of seeds and fruits of a number of species of 

 plants. 



The author determinetl the amount of carbon dioxid occurring within the 

 pericarp of various leguminous plants. It was found to be less in the light than 

 in darkness, and a confined atmosphere within the pericarp was found necessary 

 to the development of the seed. 



In a series of experiments with peas in which very immature pea pods were 

 cut In half lengthwise at right angles to the dorsal suture, the wounds healed 

 readily. The peas when matured were about half the normal size, and Instead 

 of being round were lenticular In shape. 



In studying the effect of light on the development of seeds and fruits the 

 pericarps of several species of plants were Inclosed in paper bags, .some of 

 which were double, representing diffused light, while others were black, the 

 light being completely excluded. As in the case of development in confineii air, 

 the author found that light was absolutely necessary to the beginning of the 

 development of the fruit. After a brief period of development of the embryo, 

 light was no longer necessary and Ihe development was found to proceed in dark- 

 ness with a somewhat reduced dry matter In the fruit. The amount of ash 

 seemed to be increased with the diminution of the light. The sugar and free 

 acids in the fruit varied with the different species. 



The determination of the optimum intensity of light for plants at differ- 

 ent stages of development, II. Combes {Ann. Sci. Nat. Bot., 0. ser., 11 {1910), 

 No. 2-lf, pp. 75-25.'i, pis. 5, figs. .'i2; ahs. in Compt. Rend. Acad. Sci. [Paris], 150 

 {1910), No. 25, pp. 1701, 1702). — A study has beeu made by means of various 



