SPLANCHNOLOGY 151 



The Caeca (Fig. 31, No. n). Location. The fowl has two caeca 

 extending forward from their point of origin at the juncture of the 

 small and large intestine. 



Shape. The caeca average 7.61 inches in length. They are targe 

 in caliber toward the blind extremity and are constricted near their 

 origin. 



Structure. The parietal coats are continued from the small 

 intestine. 



Ebarth has described an elevated body in the caecum, which is 

 located about 4 millimeters from the opening and is composed en- 

 tirely of lymphoid tissue. 



FIG. 374- Photomicrograph of a transverse section of large intestine and 

 oviduct just anterior to the cloaca, showing the tubular glands, of the large intes- 

 tines, mucosa of oviduct with intervening structures, i, The tubular glands of 

 large intestine, or rectum. 2, Muscular wall of intestine. 3, Wall of the ovi- 

 duct. 4, Mucosa of the oviduct. 



The caeca are usually partly filled with a soft pultaceous material 

 of a pasty consistency. 



The Cloaca (Fig. 31, No. 13). Location. The rectum opens by a 

 circular, valvular orifice into the dilated portion just in front of the 

 anus, which dilatation is called the cloaca. 



Shape. The cloaca is saccular in shape. 



Structure. The cloaca is divided into two portions, the copro- 

 deumal and the urodeumal. That portion of the cloaca into which 

 the intestine empties is called the coprodeum; and the ureter and 



