AGRICULTURAL BOTANY. 135 



of grass seedlings as typified by Avena, Zea, and Triticum, and the anatomy of 

 certain other mouocotyledonous seedlings as compared with that of the grosses, 

 the authors hold that the key to the morphology of the grass embryo lies in the 

 morphology of its seedling as interpreted by comparison with seedlings of the 

 other monocotyledons. A list is given of the principal papers which have ap- 

 peared since 1.ST2 relating to the embryo and seedling of the Graminefe. 



A method of obtaining' complete germination of seeds in CEnothera and of 

 recording the residue of sterile seed- like structures, B. M. Davis {Proc. Nat. 

 Acad. ScL, 1 (1915), No. 6, pp. 360-363). — Reporting results of tests with about 

 50 species, races, or hybrids of GEnothera, the author claims that genetical re- 

 search must adopt methods of securing rapid and complete germination of the 

 viable seeds and conservation of the remainder in a way suitable for con- 

 venient observation, If serious vitiation of results is to be avoided. The method 

 employed by the author is described, with its advantages, and methods of has- 

 tening germination of Oi^nothera are also discussed, with practical adaptations. 



Investigations in the field of the physiology of nutrition of higher plants 

 by the methods of isolated nutrition and sterile cultures, I. Shixlov 

 {Izsliedovanim v oblasti flz'iologU pitaniia v''isshikh rastenii pri pomoslichi 

 metodov isolirovannago pitamia i stcrirn'tJcJi kuVtur. Moscow, 1913, pp. 213, 

 figs. 20; rev. in ZJmr. Opiitn. Agron. (Russ. Jour. Expt. Landw.), 15 (191^/), No. 

 1, p. 65). — In this book are collected the results of experiments carried out 

 during the years 1900-1912. 



Ammonium sulphate is deemed injurious to the plants, not primarily as such, 

 but by its strong physiological acidity. The application of the method of 

 isolated nutrition has fully demonstrated the possibility of nourishing plants by 

 furnishing separate parts of the root system with portions of the nutritive 

 mixture. 



The role and function of mineral salts in plant life, D. M. Rabinovitch 

 ([Trai-.] Inst. Bot. Univ. Geneve, 8. ser.. No. 11 {19Vf), pp. 2If, figs. 5).— The 

 author reports a study on the assimilation of nutritive mineral materials by 

 Raphanus sativus, also on the influence of calcium carbonate and magnesium 

 carbonate on the development of Digitalis purpurea,. The results as shown by 

 analysis after stated periods are presented in tabular and graphical form as 

 regards R. sativus. 



The tests with D. purpurea show increasingly injurious results corresponding 

 to an increase of calcium carbonate or of a mixture in equal proportions of this 

 salt with magnesium carbonate, but the increase of injury was much less 

 marked when dolomite was substituted for the mixture. The toxic effect seems 

 to be correlated with the degi'ee of alkalinity. 



Contribution to the study of circulation, B. H. A. Groth (Neio Jersey Stas. 

 Rpt. 1914, PP- 331-33 Jf, pi. 1, fig. 1). — Studies are reported on the circulation 

 of sweet potato in which it appears that the sweet potato has difficulty in .stor- 

 ing starch in submerged soil, but there is little difficulty in doing so in air-dry 

 soil if any portion of the stem has access to water. The sweet potato seems 

 able to form aerial roots if the soil in which it grows is covered by stagnant 

 water, and it may store starch in its stem if the roots are prevented from grow- 

 ing properly. 



Winter rest in twigs of witches' brooms, H. C. Schellenbeeg (Ber. Deut. 

 Bot. GeselL, 33 (1915), No. 2, pp. 118-126).— It was found that witches' brooms 

 in winter usually responded more quickly than normal parts of the same tree to 

 temperature and moisture conditions -suitable to bud development, but that this 

 priority of response decreased as spring approached. It is believed that no in- 

 herent tendency to rest is present in witches' brooms, but that normal condi- 



