834 



SCIENCE 



[N. S. Vol. XXXVI. No. 937 



fat stain Sudan III., if introduced into an 

 animal per os, stains t^e fatty acids of the 

 food, and that this stain is not lost during 

 the circulation and deposition of these bodies. 

 Furthermore, any fat already deposited in the 

 tissues is not stained by Sudan III. fed in 

 this way. This furnishes a method of ob- 

 serving the movement and deposition of fatty 

 acids vsrithin the body. The original plan of 

 the present experiments was to feed Sudan 

 III. to chicks of both sexes at regular inter- 

 vals from the time of hatching on, and then 

 by examination of the testes and ovaries to 

 determine at what stage of development the 

 deposition of fat in the interstitial cells of 

 these organs began, if it occurred at all. It 

 was thought probable a priori that the begin- 

 ning of active deposition would coincide with 

 the beginning of the rapid growth of the 

 sexual organs, which marks the onset of their 

 functional activity. 



This was found not to be the case. Experi- 

 ments were begun with Barred Plymouth Rock 

 chicks of both sexes, taken from the incubator 

 as soon as they had dried ofF after hatching. 

 To an equal number of individuals of each sex 

 Sudan III. was given in each experiment. 

 The dose was .02 gm. This was enclosed in 

 a very small gelatine capsule, made by cutting 

 down a regular No. 5. The chick's mouth was 

 held open and the capsule carried down into 

 the crop by means of fine forceps. A prelim- 

 inary lubrication of the capsule in pure gly- 

 cerine rather aided the administration. One 

 male and one female in each experiment were 

 not fed Sudan III., and these served as con- 

 trols. In each experiment the total amount 

 of Sudan III. fed was either .02 gm., .04 gm. 

 or .06 gm., the ingestion of the larger amounts 

 being spread over two or three days respect- 

 ively. The maximum dose given in each 

 twenty-four hours was .02 gm. Twenty-four 

 hours after the ingestion of the last dose the 

 birds were killed and the ovary, or testes, and 

 samples of the body fat were removed and 

 compared with the same organs and tissues 

 taken from the controls. The result was that 

 in all cases there was a distinct pink stain 



visible in the ovary or the testis of the birds 

 fed the Sudan III. With the very small dose 

 of .02 gm. the stain was faint, but with the 

 large doses much more pronounced. This 

 result shows that even with just-hatched 

 chicks, in which the primary sex organs are 

 certainly in a sexually non-functional condi- 

 tion, fat is being deposited in hoth testis and 

 ovary. 



The same result was obtained with chicks 

 one week old. Sudan stained fatty acids were 

 deposited in the primary sex organs. In view 

 of these results there clearly was no point in 

 continuing the experiments at regular inter- 

 vals up to adult life. Consequently this was 

 not done. 



In order to test more fully the novel ob- 

 servation that metabolized fat is deposited in 

 the testis an experiment in Sudan III. feeding 

 was carried through with two adult males, one 

 an adult male of the Golden Pencilled Ham- 

 burg breed, and the other a cross-bred male. 

 These birds were in full sexual vigor, with 

 large testes. The Sudan III. was fed as fol- 

 lows: The G.P.H. 3, No. 2,494, was fed one 

 capsule containing Sudan III. on each of 

 four successive days. Each capsule contained 

 .15 gm. of Sudan III. The other bird (No. 

 2,196) was fed three capsules (one per diem) 

 successively. The amount of stain in each 

 capsule was the same as before. The result of 

 these experiments was exactly as before. There 

 was an abundant deposition of pink stained 

 fat in the interstitial tissue of the testes. 



Putting all the facts together the following 

 conclusions would appear to be justified: 



1. A part of the metabolized fat from the 

 food is carried directly to the primary sex 

 organs (ovary and testis) and deposited in the 

 interstitial tissues of those organs. 



2. The amount of such deposited (and, in 

 the subsequent chemical changes, probably 

 elaborated) fat appears to be sufficient to 

 account for the greater portion if not all of 

 the fat which has been observed by histological 

 methods in the interstitial tissues of the sex 

 organs. 



3. The deposition of fat in testis and ovary 



