1917] AGRICULTURAL BOTANY. 223 



nounced supporting the view tliat complex protoplasmic metabolites are specifi- 

 cally modified in relation to genera, species, and varieties, and hence that 

 difference In corresponding substances constitutes a specific means of differen- 

 tiation as to relationship in both plants and animals. It is stated that while 

 the methods of investigation employed differ widely in character, the results 

 are remarkably harmonious in the demonstration of certain principles of 

 fundamental importance in normal and abnormal biologj\ Each property is 

 claimed to be an independent physico-chemical character unit, each method 

 and each reagent being an independent means of differentiation, so that results 

 produced by one reagent do not indicate what will follow the employment of 

 another. However, the property values thus determined can be reduced to 

 figures, and when these are charted it can be seen that the sum total of these 

 values is, in case of each starch, as distinctive of genus, species, variety, or 

 hybrid as are ordinary botanical characters. A hybrid may be definitely 

 referred to its true parentage, also the hybrids of separate crosses may be 

 recognized as such. Corresponding histological examinations of plant tissue 

 associated with macroscopical investigation have confirmed the results of the 

 starch investigations, and strengthened the belief of the author that vital 

 peculiarities may be resolved to a physico-chemical basis. 



Notes on the anatomy of the young tuber of Ipomoea batatas, Floeence A. 

 McCoKMicK (Bot. Gaz., 61 {1916), No. 5, pp. 888-398, figs. 8).— This is an ac- 

 count of a study of sweet potato in line with that of Kamerling (E. S. R., 33, 

 p. 27) and of other autliors named. 



Biochemical and physiological study of the rest period in the tubers of 

 Solanum tuberosum, C. O. Appleman {Bot. Gaz., 61 {1916), No. 4, pp. 265-294, 

 fi,gs. 2). — This work has been noted from another source (E. S. R., 32, p. 129). 



The vitality of seeds passed by cattle, D. Milne {Agr. Jour. India, 10 

 {1915), No. 4, pp. 353-369). — From the experiments reported it is concluded 

 that uncrushed wheat grains, etc., intentionally or accidentally fed to cattle 

 working on pure culture plats during or just before seeding time are a source 

 of serious danger to the purity of the crops. 



The roots of herbaceous plants, A. P. Modestov {Kornevaia Sistema Tra- 

 vtanisVkh Rastemi. Moscow: I. N. KiisJinerev, 1915, No. 1, pp. 138, pis. 3, 

 figs. 38). — This collection comprises four contributions. The first deals with 

 differences in the growth attained by roots in various groups of cultivated 

 plants, the second with the length of roots attained under conditions of natural 

 development, and the third with the root system of flax. The fourth gives a list 

 of related contributions, comprising over 500 titles. 



Stomatal structure and function in Camellia (Thea) japonica, Magda Heil- 

 BEONN {Ber. Deut. Bot. Gesell, 34 {1916), No. 1, pp. 22-31, figs. -4).— It is 

 claimed that in C. japonica the walls of the guard cells are lignified and im- 

 mobile except in case of very young leaves in which the stomata can still open 

 and close. It is stated that in three species of Thea more or less lignified 

 stomatal cells have now been demonstrated, namely, T. viridis, T. assamica, and 

 T. bohea. 



The periodicity and distribution of radial growth in trees and their rela- 

 tion to the development of "annual" rings, J. C. Geossenbachee {Trans. 

 Wis. Acad. ScL, Arts, and Letters, 18 {1915), pt. 1, pp. 1-11). — Certain facts 

 observed in a study previously noted (E. S. R., 22, p. 650) have led the author 

 to a reexamination of the extensive literature bearing upon irregularities in the 

 time of commencement and closing of cambial activity, and a discussion is 

 herein given of radial growth and the factors thought to determine its distribu- 

 tion, the author reserving for a separate paper the results obtained from a 



