FIELD CROPS. 535 



smaller and younger tubers are richer in nitrogen than larger and older ones, 

 and that the error in determining starch from specific gravity tables is much 

 greiiter than is generally supposed. Selections were made to determine whether 

 the fluctuations in a chemical constituent are transmitted by tuber propagation. 

 One plat in 1902 was planted with tubers containing an average of 2.95 per cent 

 of nitrogenous matter in the fresh substance. A second plat was. planted with 

 low protein selections, the average nitrogenous matter in the fresh substance 

 being 1.78 per cent. The composition of the tubers harvested did not indicate 

 a definite response to selection for high or low protein, although the average of 

 nitrogenous matter when calculated to a water-free basis was 2.11 per cent 

 higher in the high nitrogen selections than in the crop from the low nitrogen 

 selections. In 1903 similar selections were again made, but from other potatoes 

 than those grown on tliese two plats, and it is not considered that very definite 

 conclusions can be drawn from the results secured. It is pointed out, however, 

 that there is a difference of 0.81 per cent in dry matter in favor of the high 

 protein plat. Attention is also called to the fact that the low protein potatoes 

 were larger, and i* is pointed out that the higher dry matter should have ordi- 

 narily been expected from the low protein potatoes on account of their greater 

 size. A difference of total nitrogenous matter in favor of the high protein plat 

 of 0.33 per cent on the fiesh basis and 1.61 per cent on the dry basis is recoi-ded. 



In general statements on the improvement of the potato the author presents 

 three possible methods of improvement : (1) The crossing of desirable plants and 

 raising of many seedlings under controlled conditions; (2) selections of the most 

 desirable fluctuations among the plants and tubers of a variety; and (3) selec- 

 tion of discontinuous variations, and a study of ways of causing them, a possible 

 example being tlie so-called graft-liybrid. 



Irish seed potatoes in England, 1907 (Dept. Agr. and Tech. Iiistr. Irelnnd 

 Jour., 8 (1908), No. 2, pp. 25-i-259). — The results shown in tables and dis- 

 cussed indicate that Irish seed produces much heavier crops in England than 

 English seed, even when the English seed is changed from one district to 

 another. It is recommended that for the purpose of supplying the English 

 market with seed from Ireland varieties popular in England should be grown, 

 only seed pure and true to name of well-selected tubers should be put on the 

 market, and the seed crop should be slightly immature to favor early ripening, 

 the production of vigorous iilants and of heavy yields. 



Solanum comniersonii violet and the Blue Giant, G. H. Pethybridge (Dcpt. 

 Agr. and Tcdt. Instr. IrrUnid Jour., 8 {1908), No. 2, pp. 2Jil-253). — The results 

 of this comparison led to the conclusion that the claims for S. comniersonii 

 violet regarding special cropping power, suitability to wet soils, disease and 

 frost resistance, and excellence of flavor have not yet been established for 

 Ireland, and that the variety if not absolutely identical with the Blue Giant 

 so far resembles it that the enhanced price of seed for S. commcrsonii is not 

 justified. It is stated that far better varieties are already in cultivation in 

 Ireland than »S'. comniersonii violet. 



Dwarf Essex rape for winter forage, J. M. Scott {Florida St a. Bui. 95, pp. 

 21-25, figs. 2). — Brief directions for the culture of rape and its use for feed are 

 given, and the results of culture and fertilizer tests are reported. Rape at this 

 station has given yields ranging from 27,200 to 33,296 lbs. of green forage per 

 acre. On September 2.5, 1907, plats 1 and 2 were sown in drills 30 in. apart on a 

 very light sandy loam soil. December 21 plat 3 was sown. On September 25 

 plat 1 received 389 lbs. per acre of a complete fertilizer, plat 2, 778 lbs., and 

 plat 3 on December 21, 61,5 It>s. Plat 2 received a second application of 389 lbs. 

 on February 10, 1908. The" best yield, which was secured from two cuttings, 



