giitlier before being expelled from the body. The urinal duet 

 o]jening' into this reservoir is a very important factor in study- 

 ing the digestibility of feeds in poultry. The fact that the 

 urine and tlic fWces mix before being expelled makes it very 

 diiRcult to study the digestion of protein, particularly because 

 in the fseoes we find the undigested portions of the feed and 

 in the urine the nitrogenous materials that come from the 

 broken-down cells of the body. As these mix before being 

 expelled, it is xevy hard t(^ determine how much of the nitro- 

 gen comes from the indigestible portions of the feed and how 

 nuich from the urine. The entire leng-th of the digestive ap- 

 paratus of the hen is about five feet, varying somewhat in 

 different individuals. Some think that there is a relation be- 

 tween its leng-th and egg production, Init more data will l)e 

 needed to verify this theory. 



The process of digestion is somewhat as follows : the food 

 is swallowed by the hen and remains in the croj:* for a time 

 to be softened. It then passes, into the stomach, where it is 

 mixed with gastric juice which acts \\\)<m certain portions of 

 the food. From here it passes into the gizzard, where it is 

 ground and thoroughly mixed with the gastric juice already 

 mentioned. It then leaves the gizzard by way of the intes- 

 tines, where it is mixed with bile from the liver and pan- 

 creatic juice from the pancreas. These are very }X)werful 

 digestive juices, and most of the food is accordingly digested 

 in the duodenum, or the first twelve to eighteen inches of 

 the intestines; but there is also an intestinal juice secreted 

 by the lining of the intestines that acts u|X)n the undigested 

 portions of the food and completes digestion. The digestive 

 ap])aratus of the goose or the duck differs from that of the 

 hen in that there is no cro]i. The feed tliey eat remains in 

 the gullet, which becomes more or less distended, until it 

 passes through the stomach to the gizzard. This difference 

 is probably due to the early habits of the birds. The geese 

 and ducks, being water fowl, were able to eat food almost 

 continually, whereas the original hen found it necessary to 

 store up her food on account of her wandering habits. A 



