digestion experiments with poultry. 32i 



Apparatus for Collecting the Feces. 



Fowls are very sensitive and object seriously to any attach- 

 ments, that interfere with their freedom of motion. The hens 

 used were much more annoyed than the capons which, after a 

 few vigorous efforts to free themselves, would calm down and 

 submit quietly. The various devices used by other experiment- 

 ors were studied and from suggestions gained thereby the fol- 

 lowing form which is shown in the cut on page 324 was de- 

 vised and adopted. It was made of a rectangular piece of pure 

 gum sheet rubber of sufficient size to make a tube 8 inches long 

 and 3 inches in diameter. The edges were firmly cemented 

 together and a ring was cemented to the top at an angle of about 

 30 degrees to keep the opening sufficiently distended and hold 

 the bag in place. The lower end was closed by means of a 

 screw clamp which could be readily taken off and allow the 

 feces to be removed without removing the apparatus from the 

 bird. It was held in place by 4 pieces of tape attached to the 

 ring, the two upper pieces were carried up over the bird's back 

 and joined just in front of his tail, then the ends were carried 

 forward, passed under and around the wings and tied back 

 of the neck. The two lower pieces were carried under the 

 body, brought up in front of the wings and tied with the others 

 back of the neck. Arranged in this way very little difficulty 

 was experienced in keeping the bags in place and after a few 

 hours wearing the birds appeared to be troubled very little by 

 them. It was necessary, however, to use care in adjusting the 

 straps ; if drawn too tightly they were liable to chafe and if too 

 loose the bag would not stay in place. The feces were removed 

 through the opening at the bottom twice daily and at the end of 

 the period any adhering particles were washed out with alcohol. 



Methods of Analysis. 



The foods used in the experiments were analyzed by the offi- 

 cial methods given in Bulletin 107 (Revised), also the feces 

 as far as possible, but in the case of the latter, as urine and 

 solids are voided together, the amount of protein undigested 

 could not be found by making the usual total nitrogen deter- 

 mination. In the urine of mammals the main portion of the 

 nitrogen, representing the proteid digested, occurs in the form 

 of urea and very little is present in the form of uric acid, while 



