528 EXPERIMENT STATION RECORD. [VeL.40 



found on the middle lobe of the leaf to determine whether variations were due 

 to genotypic differences or were merely of a phamotypic nature. The material 

 studied included plants derived from the same clone and observed through 

 three successive years, plants from the same clone grown the same years but 

 under different environmental conditions, plants from different clones, and 

 plants obtained through hybridization. Statistical methods were applied to an 

 interpretation of the results, and the data presented Lb tabular form and fully 

 discussed. The conclusion is reached that although the number of teeth in the 

 margin of the leaves of the hop plant was largely affected by environmental 

 conditions, there were nevertheless marked clonal differences which are believed 

 to be entirely independent of external Influences. 



Studies of selections of two cultivated oats, L. I>.\mi.i. and EL Mi£ge {Ann. 

 Soi. Nat. /•'"/.. .''. ser., 20 (1917), No. 1-6, pp. 289-308, figs. 6; aba. in Internal. 

 Inst. Agr. [Rome], Internat. I'< v. Soi. <>/<</ Pract. Agr., V (1918), Va, ?. /</>. 806- 

 808). — The authors describe work, conducted over a period Off four years with a 

 white and a black variety of oats, in which they mad.' observations of the inherit- 

 ance of c.-rtain grain characteristics. Four types of -tain were recognized with 

 respect to their location iii the spikelet and were designated as single, external, 

 internal, and intermediate The yield of -rain and straw from the different 

 types, the proportion per I.immi -rains of the different types obtained in the two 

 varieties and in the progeny of selected Bead, the weight of tin' different types, 

 and the proportion by weight of grain and of flumes comprised the points 



Studied, It was concluded that, at leasl in the case Of these tWO varieties, till' 



morphological differences in the -rains are net transmitted to their offspring. 



An account of an experiment to determine the heredity of early and late 

 ripening in an oat cross, A. Si. ('. CapOBR (J OUT. Oenetiot, ? (1918), \<>. /. /»/<. 

 2^7-257, /in- t).- Statistical data are presented en the exact maturation values 

 of an entire !•'.• generation as established by the I", progeny of a cross between 

 early and late ripening oats. Conclusions are reached similar to those arrived 

 at by lloshino in his work with rice i H. S. EL, ;«."., p. 328). 



Mesdag, a weak-strawed, large-grained type, was used as the early parent ami 

 Hopetown, ;i Bmall-grained, profusely tillering type, as the late parent a total 



of Km; 1". heads were rubbed out and planted the same day. a tow of each of 



the parents also being sown in proximity to the rest of the crop. Each row 

 contained 24 grains, The Mesdag row began ripening Augusl 10 and finished 



August 24, while the Hopetown row began ripening September 1. 



N'ii row was as late as the late parent nor as early as the early parent 

 although two rows extended only two and three days, respectively, hex,. ml the 

 Mesdag period, starting early, 22 other rows ripened over the period between 

 the parental times and tinished the first day of the SopetOWB harvest. It i- 

 concluded that early and late ripening are Memieiian characters, but that they 

 are dependent upon more than one factor, possibly three. ]\ plants, apparently 

 homozygous for one of these, were definitely early in the sense thai their Ft 

 progeny all attained complete ripeness before any individuals of the lale parent 

 had matured. Etomoeygosis in all three factors was apparently required bo 

 produce the two perfectly early rows. The diversity in the time of ripening of 

 the other 22 early ripeners is thought to support the inference that although one 

 factor is here constant and homozygous, thus Imparting a common measure 

 of earliness. the other two, in various heteroaygOUS and homozygous comhina 

 tions. are responsible for the different incidences of the greatest intensity of 

 this earliness. 



"There CUD be little doubt, too. that the extent of the tillering has much to 



do with the rate, of ripening. The tillering power of late forms is always i; I ; 



that of early, very i r. Owing to the concentration of growth anion- carl\ 



