898 CETACEA. 



small recesses, and which exist for the reception of the divisions of a villous tuft 

 of the chorion, are produced hj deep anastomosing offshoots from the primary strands 

 of memhrane. The tuhular orifices already mentioned, and some of which are shewn 

 as larger black dots on figure 4, appear to me to result either from hypertrophy of the 

 mucosa immediately around them, or from a contraction of the strands of radiating 

 fibres, but both causes may originate them. I have generally found that when 

 pressure was exercised on one of these orifices from without, by pressing the wall 

 of the uterus inwards, that the uterine mucosa becoming stretched exposed a smooth 

 spot at the base of the tubular recess. I Lave also frequently carefully slit them 

 open under the microscope and found a similar smooth surface in their depths, but 

 at the same time I have not unfrequently opened recesses and everted them by 

 pressure to find them terminating in no smooth area. When a bare surface does 

 occur at their bases, they are identical structurally not with the narrow bare tract 

 opposed to the chorionic area of the umbilical vessels nor with the smooth surfaces of 

 the OS uteri internum and the Eallopian poles of the horns, but with the small bare 

 spots distributed generally over the surface of the gravid mucosa on which the 

 orifices of utricular glands may be observed. I am therefore disposed to regard 

 these tubular recessess as the equivalents of the " funnel-shaped crypts " of Prof. 

 Turner* in Orca gladiator, and which he at first thought might probably be merely 

 the widened mouths of utricular glands. They appear, as I have said, to be bare 

 spots, the openings of glands, around which the interglandular substance of the mucosa 



areas wliicli formed a series of furrows parallel to tlie former. Besides the minute crjpts there were 

 many inf undibuliform recesses scattered over tlie mucosa. Many of the latter when pressure was exercised 

 on them from the outside of the womb were everted, and displayed at their bottoms round bare spots, one to 

 each recess, with strands of membrane radiating from its sides. In the furrows already mentioned, numer- 

 ous glistening smooth spots were arranged in lines, a file of spots to each furrow, but others were irregularly 

 scattered on the uterine surface, because the linear arrangement was not uniformly prevalent, although 

 it was general. These bare spots, when the uterine mucosa was not stretched, assumed the form of 

 shallow depressions, but when it was pulled out their smooth nature became more apparent, and in the 

 centre of almost every spot a small orifice could be detected by the naked eye. 



Besides these fine furrows and ridges parallel to the long axis of the horn, the uterine mucosa was 

 traversed at irregular intervals by clear glistening fine lines at right angles to the former and separated 

 from each other by intervals of about half an inch, while others were much more remote from one 

 another. These transverse lines, when the uterine wall was stretched, were seen to be composed of a 

 linear series of minute smooth spots, each having an opening in its centre, the mouth of an utricular 

 gland. It is evident, therefore, that these bare spots, both in longitudinal and in transverse series, are 

 the structural representatives of the bare spots in the uterus of the pig, the standard of comparison for 

 diffuse placentge. Besides the bare spots and fine lines the surface of the uterus had no bare areas at the 

 poles of either horns, and more remarkable, there was no bare surface corresponding to the extensive 

 branching nude surface of the chorion following the umbilical vessels which I have already described. 



In a two-humped camel, at the full time, the uterus had a cryptose structure, as regular and beautiful 

 as the cellular mass of a compound Bryozoan, but irregularly covered over with numerous bare glistening 

 spots, each perforated by a glandular orifice. There was no bare area at either pole of the uterus, but a 

 portion of the mucous surface of the Fallopian tube, owing to the extension of the organ, appeared on its 

 wall ; there was, however, an irregular limited bare area on the dorsal surface of the uterus at the os 

 internum. The chorion was finely villous all over equally at both poles, and there was no trace of the 

 bare area of the chorion of Manis, Platanista, Orcella, and the Ta^ir, but it was studded over with bare 

 spots corresponding to those of the uterus. 



1 Trans. Eoy. Soc. Edin. 1871. 



