464 EXPERIMENT STATION RECOEB. 



" There Is little difference in the effects on the secretion of bile during the 

 first six or seven hours between the diets of bread, butter, and meat, if these 

 substances be administered in quantities of corresponding caloric value. In the 

 case of bread the diminution in secretion occurs sooner than in the case of butter 

 or meat. 



" Starvation tends to diminish the secretion of bile and the excitatory effect 

 of feeding on the liver cells. 



" The following substances introduced into the stomach cause an increased 

 secretion of bile: Raw white of egg (if digestion occurs), boiled egg white, fat 

 and oil, soap solution, acids (very marked), Witte's peptone, Liebig's extract of 

 meat, and bile salts, or bile. . . . 



" The following substances eaten or introduced into the stomach produce little 

 or no effect : Pure cane sugar, cakes of baked starch and sugar, water, and a 

 solution of sodium bicarbonate." 



The influence of temperature and humidity in closed rooms on the hum.an 

 organism, K. Hintze {Ztscftr. Hijg. u. Injektionskrank., 80 (1915), Xo. 2, pp. 

 171-183). — A large number of experiments are reported in which was studied the 

 effect of high temperature and humidity upon the human body. In more than 

 half of the tests the temperature was over 30° C. (86° F.), and in some cases it 

 was as high as 40°, with a humidity of 50-60 per cent. At the lower tempera- 

 ture a humidity of from 70-90 per cent was tried, and at 20-30° the air was satu- 

 rated. 



With two or three exceptions the subjects endured the high temperature and 

 humidity very easily, and no particular ill effects were experienced. 



, ANIMAL PRODUCTION. 



Genetic studies on a cavy species cross, J. A. DETLErsE:^ (Carnegie Inst. 

 Washington Pub. 205 (1014), pp. 13-',, pis. iO).— This paper is based on a study 

 of the wild Brazilian guinea pig (Carta rufescens), the common domestic guinea 

 pig (C. porcellus), hybrids between these, and subsequent progeny obtained In 

 the next eight generations by various matings. About 1,800 animals, wild or 

 hybrid, entered in one way or another into exiieriments on color, growth, size, 

 and fertility. Besides these, approximately GOO guinea pigs, living under the 

 same conditions in collateral experiments, served as a basis for necessary com- 

 parisons. 



In part 1, which deals with color and coat characteristics, the following gen- 

 eral conclusions are reached : " C. rufescens Is homozygous In agouti, black, 

 brown, the extension factor, smooth coat, uniformity, intensity, and short 

 hair. Hybrids of any color variety can be produced by mating it to the 

 guinea pig. The color and coat characters of C. rufescens are dominant la 

 every case, except as regards roughness and texture of coat and possibly the 

 agouti factor. The hybrids have the zygotic color formula which one would 

 expect to obtain by mating a pure agouti strain of guinea pigs to some 

 other color variety of guinea pigs. The agouti of hybrids, though always 

 epistatic to the nonagouti condition of the same, is subject to modification as a 

 result of the cross. This modified wild agouti is very distinct from the tame 

 agouti and is recessive to it. The two segregate clearly in the F2 generation. 

 Both are allelomorphic to each other and to their absence. Hybrids were pro- 

 duced homozygous in agouti, yet bearing the wild and the tame agouti. Rough- 

 ness derived from the tame guinea pig is very imperfectly dominant over the 

 smooth wild coat. This incomplete dominance is lost In later, more dilute, 

 wild-blooded generations, and the rough coat becomes normally dominant. 

 The uniform coat of the wild Is dominant to the spotted coat of the tame. 



