PRAIRIE FARMER'S POULTRY BOOK 



A knowledge of all these sections of a fowl is necessary to 

 comprehend the descriptions of purebred specimens. They 

 perform very important functions and are designed for pro- 

 tection, locomotion, obtaining food, etc. 



Internal Systems and Structures 



In a study of the internal structures of a hen we find nine 

 important systems of organs, each having important work to 

 accomplish. They are: Skeleton, respiratory, circulatory, di- 

 gestive, excretory, reproductive, muscular, nervous, and tegu- 

 mentary. 



The Skeleton 



The skeleton is the bony framework of the body. A bone 

 consists of the periosteum, the white fibrous covering that 

 supplies nourishment; bone-proper, consisting of the carbon- 

 ate of lime and phosphate of lime ; and the marrow, or central 

 soft tissue, whose chief work is to help in making red blood 

 cells. 



The parts of the skeleton are : 



SKULL: 



Mandibles, upper and lower jaws. 

 Cranium, bony box containing the brain. 



NECK: 



13 vertebrae, the one next the cranium being called the atlas. 



TRUNK: 



Dorsum, or back, comprising the seven thoracic vertebrae to 

 which the seven pairs of ribs are attached. 



Sacrum, a term used to comprise all the vertebrae between the 

 thoracic and the caudal vertebrae. They are fused together so as 

 to form one solid structure. 



Caudal Vertebrae, six in number, which support the structures 

 of the tail. 



Pelvis, comprising three distinct bones on each side, known as 

 the ilium, ischium and pubis. These form a protection for the kid- 

 neys and other viscera. They unite to form a socket for the 

 femur, and they are fused to the sacrum so as to form a contin- 

 uous arch. The points of the pubis, which can be located just 

 below and on each side of the vent are known as the pubic bones, 

 or so-called "lay-bones." 



Shoulder circle, comprising: 

 Scapula, or shoulder blade. 



Caracoids, strong bones extending from sternum to 

 shoulder. They form a point of attachment for the humerus 

 and the hold the sternum and shoulders apart. 



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