The Diagnosis of the Diseases of Poultry 45 



called the duodenum (6), forms a U-shaped loop. It consists 

 of a left or proximal and a right or distal limb. Between 

 these two limbs is situated an important digestive gland, 

 the pancreas (7). Without any line of demarcation the 

 duodenum is continued as the long, small intestine (8) back 

 to the point of origin of two out-pocketings of the ali- 

 mentary tract called the ceca (9). The point of origin of 

 these organs marks the separation between the small intes- 

 tine lying in front of them, and the large intestine or rectum 

 (10) lying behind them. The rectum opens into the cloaca 

 (11), a somewhat dilated chamber which opens externally 

 by the vent. Into the cloaca open besides the rectum the 

 ducts of the urinary and genital systems of organs. 



On the ventral side of the abdominal cavity is seen the 

 large liver (12), consisting of a large right lobe and a smaller 

 left lobe. Attached by a fold of membrane to the proven- 

 triculus is seen the spleen (13), a small, ovoidal, red body. 

 Just in front of the liver lies the heart (14), inclosed in a thin 

 membranous sac, the pericardium. The lungs (15) are light 

 red spongy bodies which may be seen by turning aside the 

 heart, closely attached to the dorsal body wall in the tho- 

 racic region. 



Just behind the lungs is seen on the left side of the body 

 in the female the ovary (16). Except in rare cases, the 

 ovary on the right side of the body in the domestic fowl 

 degenerates during embryonic life and only the left ovary 

 remains to produce eggs. It is made up of a number of 

 spherical bodies of various sizes called ovarian eggs or oocytes. 



Behind the ovary is the oviduct (17), which in a laying 

 hen is a much coiled tube with thick glandular walls. In 

 this tube the albumen and other envelopes of the egg are 

 manufactured. At the anterior end of the oviduct is the 

 infundibulum (18) or funnel. (For further description of 

 the reproductive organs see p. 245.) 



