502 THE OVIDUCTS. 



tubular glands arranged vertically are found throughout the 

 vjhole length, with the exception of the upper attached portion, 

 of the oviducts of this species, and they are separated from one 

 another only by thin layers of connective tissue proceeding 

 from the mucous membrane. 



If the longitudinal folds of the mucous membrane that are 

 met with throughout the whole length of the canal, and which 

 attain their greatest height near the ostium abdominale, be 

 separated from one another by means of needles, a fine velvety 

 tissue, presenting minute openings, and resembling a honey- 

 comb, may be seen, excepting only at the attached abdominal 

 extremity, where the glands are less numerous. 



In transverse sections an investing membrane composed of 

 connective tissue is seen; externally to this succeeds a thin 

 layer of circular muscular fibres, on which the mucous mem- 

 brane lies. The gland tubes are imbedded in this membrane, 

 and, as already stated, they are only separated from one another 

 by the vascular connective-tissue trabeculse given off by the 

 tissue of the mucous membrane. The mucous membrane rises 

 above these in numerous longitudinal folds, between which the 

 openings of the gland tubes are visible. The tubes are lined 

 by well-defined pavement cells. The folds of the mucous 

 membrane in Man are moderately prominent, and are frequently 

 branched. Their interior is occupied by a dense cord of 

 connective tissue, in which bloodvessels and a few smooth 

 muscular elements are contained. Externally they are coated 

 by tall columnar and ciliated epithelial cells. In the further 

 course of the oviduct the folds are unbranched. 



