830 EXPERIMENT STATIO]^ PtECOEI). [Vol. 41 



distance of about 10 in., with from 2 to 4 plants per hole. A larger average 

 number of tillers per plant and larger yields have been secured by single plant^ 

 selection. 



Cross-pollination of sugar cane, H. B. Cowgill (Jour. Dept. Aijr. and Labor 

 I'arto h'iro, 3 (1!)19), Xo. /, 2>P- 1-5). — This paper has already been noted from 

 jiuother source (E. S. K., 40, p. 241). 



Varieties of sugar cane in Porto Rico, F. S. Eaele {.lour. Dept. Agr. and 

 Labor Porto Rico, 3 {1919), No. 2, pp. 15-55). — This paper comprises a discus- 

 sion of the cultural value and characteristics of sugar cane varieties grown in 

 Porto Rico, together with brief botanical descriptions of a number of the 

 varieties supplemented by a key for their identification. 



Breeding timothy at Svalof, H. Witte {Jour. Hereditij, 10 {1919), No. 7, pp. 

 291-299, figs. 7). — The author presents a brief account of the methods employed 

 in timothy breeding at Svalof, the numerous forms studied, and the results 

 secured. Characters which have received attention with regard to variation 

 and heredity include the length, thickness, and direction of growth of the 

 stem ; the number and length of internodes ; the size and color of leaves ; the 

 length, thickness, shape, stiffness, and compactness of head ; the size and color 

 of glumes, the color of anthers, and the form, color, and size of seed ; physi- 

 ological characters such as hardiness and earliness ; the quantity of after- 

 growth and stooling ability ; and disease and drought resistance. It is said to 

 be practically impossible to secure perfectly constant strains of timothy, and 

 in view of this fact the work of the plant breeder is believed to consist chiefly 

 of the elimination of characters of purely theoretical interest in an effort to 

 obtain the highest posssible uniformity in practical characters. 



Characters deemed desirable for a tiiuothy variety which is to be employed 

 in a two-year meadow include tall, not too stout, erect, comparatively stiff 

 stems with short top internodes and relatively long base internodes, vigorous, 

 abundant stooling power, profusion of leaves, perfectly fresh at cutting, rich 

 aftergrowth, hardiness, highest possible resistance to rust, convenient earli- 

 ness, and good development during the second year. A desirable variety for 

 perennial pasture, on the other hand, is described as one possessing vigorous 

 stooling power, early and abundant aftergrowth after each grazing, hardiness, 

 highest possible resistance to rust, and highly increased longevity. Good seed 

 production is regarded as eqiially important as a high hay jaeld, the following 

 characters being deemed essential for this purpose : Tall, stiff, compact, unin- 

 terrupted heads ; big, plump, vrell-colored seeds, easily remove<l from empty 

 glumes and with well-attached floral glumes ; and a high degree of self-fer- 

 tilization. 



In trials with selected sorts of timothy made during the period of 1909-1918 

 two new strains have been developed and distributed, Primus and Gloria, which 

 have produced approximately 12 and 20 per cent more green fodder per hec- 

 tare, respectively, than ordinary Swedish timothy. 



Inheritance of branching habit in tobacco, J. .Tohnson (Genetics, 4 {1919), 

 No. If, pp. 307~3.'t0, figs. 10). — Studies conducted at the Wisconsin Experiment 

 Station are described in which observations were made on the iidieritance of the 

 branching or suckering habit of toljacco in a cross between a Cuban type having 

 numerous large suckers and a Little Dutch strain possessing a few small 

 suckers. The conchisions are based largely on counts and weights of suckers 

 of the parental types and of succeeding generations made over a period of 

 years under widely varying environmental conditions, as well as upon data 

 secured when the parents and several succeeding generations of the cross 

 wei'e grown the same year under identical conditions. Data are also pre- 

 sented on correlations between the number of leaves and the number and 



