ANIMAL PRODUCTION. 1101 



are fed for two or more weeks on a milk diet, tlieir pancreatic; jnico obtained by 

 means of secretin invariably contains lactase. 



"The formation of lactase by the pancreas is a specific reaction to lactose; it occurs 

 only when lactose is given by the mouth, and not when it is injected subcutane- 

 ously. . . . 



"The lactase of the pancreas is in no way derived from that present in the intesti- 

 nal mucosa; it is formed l)y the pancreas itself, and represents a definite; adaptation 

 to a milk diet on the part of the pancreas. . . . 



"Secretin appears to have a definite composition, is in no way modified by differ- 

 ence of diet, and is not concerned in the adaptation of the pancreas to food; it calls 

 forth the secretion by the pancreas of all the enzyms jjresent in the gland at the 

 time. ' ' 



Estimation of carbon dioxid by densimetry, A. D. Waller and B. J. Col- 

 LiNGWOOD {Jour. Physiol, 30 {1904), No. 5-6, Proc. Physiol. Soc, 1903, pp. XXXVI- 

 A'A'A'JA', fig. 1). — A method of estimating carbon dioxid with a form of densimeter 

 is descril^ed. 



Note on the calculation of the respiratory quotient from volumetric data, 

 A. D. AValler and B. J. Collingwood {Jour. Physiol, 30 {1904), Xo. 5-6, Proc. 

 Physiol Soc, 1903, pp. XXXIX-XLII). — The factors which should be taken into 

 account in determining the true respiratory quotient are discussed, as well as the 

 possible sources of error. On the basis of results obtained with the densimeter, the 

 authors assert the theoretical possibility of experimentally estimating the respiratory 

 quotient without volumetric determination of oxygen. 



ANIMAL PRODUCTION. 



Experiments with fattening steers, M. Gumming ( Ontario Ayr. Col and Expt. 

 Farm Rpt. 1903, pp. 84-87). — Continuing earlier work (E. S. R., 15, p. 67), a test was 

 conducted to determine whether in fattening steers it is more satisfactory to buy 

 moderately heavy animals and feed them for a short period, or lighter, thinner 

 animals, and continue the feeding for a longer period. Eight steers weighing on an 

 average 1,271 lbs. and fed for 117 days, made an average daily gain of 2.08 lbs. at a 

 cost of 12.75 ots. per pound, as compared with 2.16 lbs. daily gain at a cost of 10.53 

 cts. made by an equal number of steers averaging 1,098 lbs. in Aveight and fed for 

 160 days. 



"Every pomid of gain in live weight costs more to produce than it will sell for 

 on the market. Any profit in feeding must come from increasing the value of the 

 carcass purchased in the beginning. Therefore, the steer which requires to be 

 increased in weight only 200 lbs. in order to be fit for market, is worth considerably 

 more per pound than the steer which requires to be increased 300 lbs." 



In order to learn the relative merits of cut and uncut hay and roots in the above 

 tests one-half the steers were fed these feeding stuffs cut and the other half whole. 

 The average daily gain on cut feed was 2.04 lbs., as compared with 2.16 lbs. on uncut 

 feed, the cost of a pound of gain in the 2 cases being 10.82 and 11.54 cts., respec- 

 tively. A little less meal and a little more hay and roots were consumed per pound 

 of gain when the feed was not cut. According to the author, it will depend upon 

 circumstances whether the slightly lower cost of a pound of gain is sufiicient to pay 

 for the labor of cutting the hay and pulping the roots. 



The value of blood meal as part of the ration for steers was studied; a lot of 8 ani- 

 mals averaging 1,250 lbs. in weight being fed 1.20 lbs. of this material per day for 63 

 days in addition to corn meal, oats, and barley. The total gain made by the lot was 

 1,085 lbs. as compared with 1,070 lbs. made by a similar lot of 8 steers fed the same 

 basal ration but no blood meal. With the former lot 4.29 lbs. meal and 0.54 lb. 



