362 EXPERIMENT STATION RECORD. 



doubtful exceptions, the inhibitory unit never remains latent or recessive 

 throughout the whole life of the horse, hence the law that " every gray or 

 roan must have at least one gray or roan parent and that two whole colors 

 can not give rise to gray or roan. Once the gray line is brolien there is no 

 reversion in a subsequent filial generation to gray ancestors." 



It is shown that while there are apparent Stud Booli exceptions to this rule, 

 they all contain a grave element of doubt. The mating of pure grays gives rise 

 to gray offspring solely. In mating impure grays together four possible com- 

 binations would occur in fertilization, each being equally likely, namely: (1) 

 Purity for the inhibitory factor, the offspring possessing a blacli skin and a 

 white or nearly white coat; possibilities of the occurrence of impurity for the 

 inhibitory factor resulting in either (2) a fine or (3) a coarse mosaic of pig- 

 mented and unpigmented hairs; and (4) a pure whole color, which even though 

 mated vpith similarly extracted whole colors will never throw reversions to 

 gray. 



Reference to the table of matings shows that the proportion of whole colors 

 to grays accords very closely to the expected 1 : 3 proportion, and an investiga- 

 tion indicates that none of the extracted whole colors from these matings ever 

 threw reversions to gray. In the mating of impure grays with whole colors 

 there are two kinds of offspring possible, impure grays and whole colors, in 

 approximately equal numbers. 



In concluding the author states that " what the heredity of coat color prin- 

 cipally teaches us is that inheritance recognizes no such limitations as unde- 

 viating tail-male or tail-female descent, and that weight of ancestry plays a 

 very minor part in heredity. In the transmission of gray it plays no part what- 

 ever, for the inhibitoi'y factor which Is resix)nsible for this condition still holds 

 its own with undiminished vigor in spite of the overwhelming preponderance of 

 whole-colored ancestry in the pedigrees of gray thoroughbreds." 



See also a previous note (E. S. R., 30, p. 673). 



Tables for statisticians and biometricians, edited by K. Peabson {Cam- 

 bridge, England, 1914, pp. LXXXIII-j-143).— This Includes 55 tables of interest 

 to statisticians and biometricians. 



Action of sugar in nutrition, A. Goxjin and P. Andouabd iCovipt. Rend. Soc. 

 Biol. [Paris'^, 7^ (1913), .No. 19, pp. 1082-10S4) .—A three-months-old calf was 

 fed for 11 weeks, during the first four weeks on a ration high in amid content 

 (potatoes and manioc), and during the last six weeks a saccharose feed in 

 which carob-bean meal predominated. During the first period the ration con- 

 tained 218 gm. of saccharose per 1,CM30 kg. weight, and during the second period 

 420 gm. The average daily increase in weight was 821 gm. in the first period, 

 and 905 gm. in the second. There was found to be a reduction in the amount 

 of urine secreted, in the urinary nitrogen, and in the nutrients digested, with the 

 increased allowance of saccharose. 



The effect of sugar on the digestion of nitrogen, A. Goxjin and P. Andouabd 

 (Compt. Rend. Soc. Biol. [Paris], 75 (1913), No. 86, pp. 550-552; ahs. in 

 Intemat. Inst. Agr. [Rotne], Mo. Bui. Agr. Intel, and Plant Diseases, 5 (1914), 

 No. 3, pp. 380, 3S1). — In experiments to determine the influence of sugar on the 

 utilization of nitrogen, pigs were fed during two periods of 42 days each, the 

 first period on peanut cake, degelatinized bone meal, and manioc roots, and the 

 second period on peanut cake, degelatinized bone meal, and Jerusalem arti- 

 chokes. 



During the first or starch period the average daily increase in weight was 667 

 gm. per head and during the second or sugar period 595 gm. The manioc starch 

 was always completely utilized, while the sugar of the artichokes was often 



