16 DISEASES OF POULTRY. 



we must) consequently, know the different organs ot 

 the body, we must know what work each organ does, 

 and how the organs are associated for the accomplish- 

 ment of a common purpose. 



Besides the digestive apparatus, we find in the bird's 

 body the nostrils, larynx, trachea, lungs and air-sacs 

 which together constitute the respiratiyry apparatus. 

 The principal functions of this apparatus are to supply 

 oxygen to the blood and receive in return carbonic acid 

 gas and watery vapor. Then, there is the circulatory 

 apparatus, composed of the heart, arteries, capillaries, 

 veins, and lymphatics, which carries the nourishment 

 and the oxygen to every part oi the body and brings 

 away the waste and worn out material. There is the 

 urinary apparatus, made up of the kidneys and the 

 ureters, which separates and removes from the blood 

 the great part of the waste of the body which can not 

 be vaporized and carried away with the air expired 

 from the lungs. There is the genital apparatus which 

 in the male consists of testes, vas deferens, and, with 

 some varieties, a penis, and in the female of ovaries, 

 and oviducts, the purpose of this apparatus being the 

 reproduction and perpetuation of the species. There is 

 the locomotive apparatus and framework of the body, 

 made up of the bones, ligaments, muscles, and tendons. 

 There is the brain and nervous system which estab - 

 lishes communication between and governs the different 

 organs and apparatus. And, finally, there is the 

 tegumentary system, which includes the skin and 

 feathers and the function of which is to cover and pro - 

 tect the body, and excrete a certain amount of liquid 

 bearing with it some soluble waste products from the 

 blood. 



