ON THE ARRANGEMENT OF THE FCETAL MEMBRANES IN THE CETACEA. 475 



The complete absence of any putridity led me to hope that a minute injec- 

 tion of the vessels of the mucous membrane might be obtained, and that the 

 relation of the capillaries to the crypts and to the uterine glands might be 

 studied. Injecting pipes were accordingly inserted into some of the uterine 

 arteries, and, with the skilled aid of my assistant, Mr Stieling, the uterine 

 system of capillaries was successfully filled with a gelatine and carmine injec- 

 tion. But before I enter on an account of the distribution of the blood-vessels, 

 it will be necessary to point out the characters of the mucous membrane itself, 

 as displayed both in vertical sections, and in horizontal sections made parallel to 

 the plane of the free surface. 



Vertical sections through the membrane confirmed the description just 

 given of the arrangement of the pits, recesses, and crypts already recognised by 

 the inspection of the free surface. The depth of the crypts was variable, but in 

 no instance did they seem to occupy more than about the superficial third of 

 the thickness of the mucous membrane, and those which passed deepest into 

 its substance had usually several shallower crypts grouped around them. The 

 form of the deeper crypts resembled more a funnel, that of the shallower a cup. 

 It may be convenient to call this part of the membrane the crypt-layer (a, fig. 4), 

 or perhaps, from its numerous capillaries, the vascular crypt-layer. 



The deeper two-thirds contained numerous elongated tubular glands — the 

 proper utricular glands — and may appropriately be called the glandular-layer 

 (b, fig. 4). It lay in contact with the muscular coat. From their tortuous 

 course and direction, the individual glands could only be followed for a com- 

 paratively short distance, and they presented different appearances in the vertical 

 and horizontal sections. As their long axes lay mostly in a direction parallel to 

 the free surface, good views of their arrangement were obtained in the horizontal 

 sections, in which the glands were seen not only to be convoluted, but to branch 

 (fig. 5). Sometimes they bifurcated, at others three branches arose close 

 together, and the branches could be traced sometimes for a considerable dis- 

 tance, but at others they formed short diverticula closed at their free ends. 

 Each branch possessed throughout an almost uniform diameter, but the portion 

 of the gland-tube situated immediately beneath the crypt layer, which may be 

 called the stem of the gland, had a wider calibre than its various branches, 

 which lay in the deeper portion of the mucous membrane. In the vertical 

 sections, again, as a rule, only short lengths of any given gland could be traced, 

 for the tubes were divided, sometimes longitudinally, but not unfrequently 

 obliquely or transversely (fig. 4, b). As it was of importance to ascertain the 

 relations of the glands to the crypts, I examined many vertical sections to see 

 if I could follow the stems of the gland tubes, through the thickness of the 

 mucous membrane, to their openings or mouths on the free inner surface of the 

 uterus. And in carrying on these observations I encountered considerable 



VOL. XXVI. PART II. 6 H 



