Diseases of the Reproductive Organs 259 



filling a large part of the left half of the abdominal cavity. 

 It is suspended from the dorsal body wall and lies dorsal 

 to the abdominal air sac. Its anterior end is expanded 

 into a large funnel which is spread out beneath the ovary 

 in such a way that the mouth of the tube faces the ovary. 



The oviduct is divided into five main parts, readily dis- 

 tinguishable by gross observation. Beginning at the 

 anterior end, there are, in order : (a) the infundibulum or 

 funnel (Fig. 57, A) ; (6) the albumen secreting portion (Fig. 

 57, B) ; (c) the isthmus (Fig. 57, C) ; . (d) the uterus or 

 " shell gland " so called (D) ; and (e) the vagina (£). The 

 functions of these different parts have already been indicated 

 (cf. pp. 248). 



The chief features in the finer structure of the oviduct 

 may be described as follows : 



Two muscular layers, an outer longitudinal and an inner 

 circular layer can be distinguished in all parts of the oviduct. 

 The inner surface of the oviduct is thrown into a number of 

 primary longitudinal ridges. The epithelium over these 

 ridges forms secondary folds. In the uterus the ridges as 

 such are lost, and instead there are a number of leaf-like 

 folds of the inner surface. 



Three types of glands are described : (1) Unicellular 

 epithelial glands occurring between the ciliated cells in all 

 parts of the oviduct except the anterior portion of the funnel. 



(2) Glandular grooves. These are accumulations of gland 

 cells at the bottom of the grooves between the secondary 

 folds of the epithelium. These are found only in the funnel 

 region. But there they occur well towards the anterior end. 



(3) In all parts of the oviduct between the funnel and the 

 vagina there is a thick layer of glands beneath the epithe- 



Fowl." Me. Agr. Expt. Stat. Bui. 167, pp. 1-20, 4 plates, 1910. 

 Surface, F. M., "The Histology of the Oviduct of the Domestic 

 Hen." Me. Agr. Expt. Stat. Ann. Rept., 1912, pp. 395-430, 5 plates. 



