1916] FIELD CROPS. 233 



Tobacco seed beds, F. Chaelan (Canada Expt. Farms Bui. 21, 2. ser. {1015), 

 pp. 51, pis. 3, figs. 13). — This bulletin is a popular treatise ou the preparation, 

 care, and management of tobacco seed beds. Detailed temperature records of 

 hotbeds, semihotbeds, and greenhouses are appended. 



On tbe inheritance of some characters in wheat, II, A. and G. L. C. Howaed 

 (Mem. Dept. Acjr. India, Bot. Ser., 7 {1915), No. 8, pp. 273-285, pis. 9).— In pre- 

 vious work along this line (E. S. R., 28, p. 638), it was assumed in view of 

 the results secured that in the crosses between bearded and beardless wheats 

 the bearded parent had two factors, one capable of producing short awns or 

 tips only and the other, when acting in conjunction with the first, resulting in 

 fully bearded plants. To obtain further data on the subject the cross was con- 

 tinued to the Ft generation, in which the behavior of selected plants confirmed 

 the results of the third generation. The forms with long tips and short tips as 

 well as the bearded and beardless plants bred true. 



For the further study of these factors short-tipped and long-tipped forms 

 isolated from the Fi of a cross between P 22, containing the two factors produc- 

 ing the fully bearded character, and A 88 (entirely beardless) were recombined, 

 and P 6, a wheat apparently carrying the long-tipped factor, was crossed with 

 P 7 which seemed to have short tips. In the recombination of the bearding 

 factors of P 22, the Fi plants were almost beardless while 59 plants in the Fj 

 ranged from 4 beardless to 4 fully bearded. In the cross of P 6 with P 7 the 

 procedure was the same and the results were similar. 



Two other cases of a cross between a bearded and a good beardless form were 

 studied. Punjab Type 9, a bearded wheat, was crossed with Pusa 4, an entirely 

 beardless form, and in the F2, 610 plants were examined. Of these, 39 were 

 beardless and 571 were awned to varying degrees ranging from fully bearded 

 to minutely tipped. Similar results were obtained in crossing BXI 77, a fully 

 bearded form, with Pusa 4. The ratio of bearded to beardless forms is regarded 

 as indicating the existence of two factors in the bearded parent. 



It was observed that the development of a bearded or beardless character was 

 not always uniform, especially in the case of cultures breeding true to long or 

 short tips. The first formed and largest ears had the longest awns, while those 

 produced later had almost no awns. It is stated that well-grown cultures 

 develop tips normally and present no difficulty in deciding whether the tips are 

 long or short, while in weaker growth the tips do not develop well and care is 

 necessary to distinguish their nature. It is further found that observations 

 on bearding are best made when the ears are still green and just before the 

 chaff begins to change in color. In order to grow complete cultures from any 

 particular plant it is advised to sow the grain in boxes and then transplant the 

 seedlings into the field, as in this way little or no loss of plants occurs. 



Studies were also made of felted and smooth chaffs as heritable characters. 

 A microscopical study of the chaff of Punjab Type 9 revealed long silky hairs 

 and much shorter ones. An analysis of the Fa and subsequently of the F2 

 generation resulted in the isolation of these two kinds of hairs and in the proof 

 that each kind is inherited separately. Three crosses were made Avhich resulted 

 in the proof that the felting in Pusa 4 is identical with that in BXI 77 and that 

 the felting in both these cases is identical with the short chaff hair character 

 in Punjab Type 9. 



Some observations on the occurrence of sterile spikelets in wheat, A. E. 

 Grantham (U. S. Dept. Agr., Jour. Agr. Research, 6 {1916), No. 6, pp. 235-250, 

 pi. 1; abs. in Science, n. ser., 43 {1916), No. llOIf, pp. 289, 290).— The results of 

 an examination of a large number of varieties of wheat with reference to 

 sterility of spikelets made at the Delaware Experiment Station in 1915 is 

 noted. 



