. Useful birds and their protection. Containing brief descriptions of the more common and useful species of Massachusetts, with accounts of their food habits, and a chapter on the means of attracting and protecting birds. Birds; Birds. VALUE OF BIRDS TO MAN. 41 refuse is voided. This is digestion. The food is often manip- ulated, crushed, or divided by the beak. It then receives saliva from the mouth, and passes through the pharynx into either the gullet (a muscular and membranous tube) or crop (a pouch), as the case may be, organs capable of great distention, and connecting with the first div
. Useful birds and their protection. Containing brief descriptions of the more common and useful species of Massachusetts, with accounts of their food habits, and a chapter on the means of attracting and protecting birds. Birds; Birds. VALUE OF BIRDS TO MAN. 41 refuse is voided. This is digestion. The food is often manip- ulated, crushed, or divided by the beak. It then receives saliva from the mouth, and passes through the pharynx into either the gullet (a muscular and membranous tube) or crop (a pouch), as the case may be, organs capable of great distention, and connecting with the first division of the stomach. Here, then, is the first receptacle of the food. Birds of prey. Herons and some other large birds sometimes fill the gullet to the very mouth, while awaiting the digestion of the food in a stomach already full. The Pelicans have also another great receptacle or pouch, ex- ternal and beneath the beak, where a store of food can be carried. Many of the smaller birds also are able, after filling the stomach, to stow away a still larger supply of food in the gullet. The stomach is large, and usually capable, by distention, of contain- ing a considerable quantity of food. The food passes from the gullet or the crop to the pi'oventriculus or glandular portion of the stomach. This is where the process of digestion begins. Mixed with salivary, ingluvial, and proventricular secretions, the. Pig. IV.— Alimen- tary canal of Blue- bird, reduced; after Auduljon. rt, 6, gul- let or oesophagus; c, proventriculus; d, gizzard; e, /, h, in- testine ; 1, cloaca. food next passes to the gizzard or muscular division of the stomach, where the food grist is ground fine. Among seed-eating birds the heavy, powerful muscles of this portion of the stomach are, with the rough, calloused stomach lining, assisted in their work by sand and gravel which are swallowed. This mineral matter takes the place of teeth in grinding the food. In vegetable-feeding birds the intestine is very long
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