ON THE ARRANGEMENT OF THE FCETAL MEMBRANES IN THE CETACEA. 477 



closely arranged around the wall of each tube, but leaving a distinct lumen in 

 the axis of the gland. The epithelial cells exhibited no appearance of degene- 

 ration, and the glands had the aspect of secreting organs in a state of complete 

 functional activity. I may mention here that in the pregnant uterus of a pig, 

 the foetus in which weighed only 12 grains, which was examined at the same 

 time, the glands had only half the diameter of those observed in this Orca. 



The mucous membrane, which formed the walls of the crypts, and in which 

 the glands were imbedded, consisted of a delicate connective tissue containing 

 numerous nucleated corpuscles (fig. 4,/). These corpuscles were in part the 

 spindle-shaped nucleated corpuscles of the wall of the capillaries, but more fre- 

 quently were proper to the tissue itself. In the connective tissue of the gland- 

 layer these corpuscles mostly had the fusiform shape, but in the walls of the 

 crypts a distinct layer of globular or ellipsoidal nucleated corpuscles was seen 

 immediately within the boundary line of the mucous membrane, which was not 

 unfrequently elevated in a gently wavy line immediately superficial to the cor- 

 puscles. From their position these cells may be called the sub- epithelial cells of 

 the mucous membrane of the crypts (fig. 4,^). In thin sections, more especially 

 where the capillaries were partially filled with the red injection, they could be 

 readily distinguished from the spindle-shaped corpuscles of the capillary wall 

 by the difference in shape, and by the same test there was no fear of confounding 

 them with the epithelial lining of the crypts to be next described. 



In many of the sections I was able to trace without difficulty the epithelial 

 lining of the crypts, and obtained the clearest views of the cells in the injected 

 portions of the mucous membrane (fig. 11, a). This lining, where it had not been 

 disturbed, was in contact with, and closely followed, the various irregularities 

 of, the mucous surface ; but in many places it had been either partially or alto- 

 gether removed, so that it is obviously readily shed from the membrane. The 

 cells of which it was composed had the appearance of a pavement epithelium, 

 though they were not larger than the broad, free ends of the cylindrical epi- 

 thelium lining the glands, with which, indeed, the epithelial lining of the crypts 

 was anatomically continuous. I examined, but failed to detect any difference 

 in shape between the cells lining the gland-crypts and those which lined the 

 crypts into which the utricular glands did not open. 



The close relation which exists between the uterine glands and the deeper 

 funnel-shaped crypts, and the manifest continuity of the epithelial lining of the 

 one with that of the other, seems naturally to justify the inference, that in the 

 pregnant cetacean, all the crypts into which the glands open are merely the 

 mouths of the glands " somewhat enlarged and widened," and thus to establish 

 a correspondence with the arrangement which Dr Sharpey first pointed out in 

 the pregnant bitch. The extent to which, if we assume the accuracy of this 

 inference, the dilatation of their mouths may have proceeded, I am not as yet 



