400 CETACEA. 



termination. This was a tedious undertaking, as the ramifications of a single gland 

 were very great, and some of the branches were so long that they were sometimes 

 mistaken for the main tube and followed up, but to end in a blind sacculus. 

 Tortuous sacculated branches were given off by the main stem close to its termina- 

 tion, (Plate XXXVII, fig. 9). As the end of the tubule was reached, it was found 

 to run for some distance longitudinally below the mucosa, and from the circum- 

 stance that it was rather firmly attached to its under surface considering its delicate 

 nature, the difficulty in tracing out the gland at this part of the research was 

 great. After frequent similar observations conducted under the microscope, I 

 was enabled to satisfy myself that the glands terminated on the surfaces at the 

 base of the recesses and on the smooth spots scattered over the free surface of the 

 mucosa. When the bare spots were examined with a hand lens, I had no difficulty 

 in detecting the existence of an opening in the centre of many of them, associated 

 in some instances (Plate XXXV, fig. 5) with a visible rounded linear eminence 

 corresponding to the course of the termination of the gland tubule. In other 

 instances, however, I failed to discover any very decided appearances of the gland- 

 ular orifices, but I consider that these failures were due to a flaccid condition of 

 the spots in which they could not be detected, and not to the absence of the open- 

 ings. I had numerous sections made through bare spots to try and demonstrate 

 the opening of a gland, but I failed, owing, I believe, to the circumstance that the 

 glands' mouths open so obliquely on the surface. I would, however, again repeat 

 that when the fresh uterine mucosa is examined under a low power and even with 

 the naked eye, innumerable bare spots can be detected, each with an orifice generally 

 near its centre, and that underneath these bare spots the tubules of the glands 

 terminate, and also at the bases of the recesses ; and the nature of these recesses I 

 have already explained. Under a moderate power, the cylindrical epithelial lining 

 of the glands is readily visible, and where a clean transverse section has been made 

 (fig. 11), the clear interior with its layer of columnar epithelial cells is at once 

 recognisable. 



Chorion. — In a specimen preserved in spirit for some time the outer surface 

 of the right horn is extremely rugose with some persistent lamellar folds radiating 

 from the pole of the cavity. There is no trace of the uterine pouch that occurs 

 in P. gangetica, although there is a slight dilatation in the corresponding portion. 

 The most non-villous portion of the chorion is that which occupies the left horn 

 and especially its two ends, the posterior surface being exceedingly rugose and in 

 persistent folds as in P. gangetica. The right pole of the left horn and the left pole 

 of the same cavity are more or less marked with lamellar folds. The left horn of 

 the chorion (Plate XXXV, fig. 2), is covered with smooth spots of the same nature 

 as in P. gangetica, but from the contracted condition of the right or non-gravid pole 

 they are very difficult to detect on it, and are much less numerous than on the left 

 pole. In transmitted light the villi are seen to be collected in small groups, but 

 they are very minute on branched depressions which correspond to the course of the 

 uterine blood-vessels. 



