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Dr. M. Watson. 



which, at some parts, formed a continuous investment to the processes; 

 whilst, at others, the epithelium having, to some extent, been abraded, 

 although a continuous covering was absent, these cells, isolated, or 

 in groups of various sizes, still adhered to the surface of the process 

 under examination. These cells closely resembled those lining the 

 alimentary canal, and were provided with a well-defined nucleus of a 

 round or oval form. I have little doubt that in the recent state 

 these cells had formed a complete investment to the maternal pro- 

 cesses. It was particularly remarked that in none of these processes 

 was there any trace of the colossal capillaries above described, but 

 that their blood-vessels consisted exclusively of capillaries of the 

 ordinary description, and exactly resembled those met with in. the 

 uterine mucous membrane. 



Professor Turner has already described, in the placenta of Cholcepus, 

 two sets of vessels which almost exactly correspond to those above 

 referred to Procyon. His observations, however, were rendered more 

 perfect than my own by the fact that he was able to inject the 

 placenta both from the foetal and maternal vessels. From the com- 

 pleteness of this injection he was enabled to decide that the colossal 

 capillary system constituted the maternal portion of the placenta, 

 whilst the capillaries w T hich presented the usual structure appertained 

 to the foetal portion. I have, consequently, endeavoured to reconcile 

 my own observations with those of Professor Turner, but in vain. 

 Of a direct connexion between the colossal capillary system and the 

 foetal umbilical vessels in Procyon, I was, of course, in the absence of 

 injection, unable to convince myself. But, bearing in mind the facts 

 (1) that in no single instance did I observe any appearance of the 

 passage of a colossal capillary beyond the placenta into the wall of 

 the uterus; and (2) the exact correspondence in structure of the 

 circum-papillate ridges with that of the uterine mucous membrane; 

 and (3) the probable continuity of these processes with the mucous 

 membrane of the uterus ; I can (subject, however, to future cor- 

 rection) see no escape from the conclusion that in Procyon the colossal 

 capillaries belong to the foetal, whilst the ordinary capillaries con- 

 stitute the vascular portion of the maternal placenta. 



Having now described the minute anatomy of the placenta, I pass 

 to that of the uterine mucous membrane. Having made sections of 

 the wall of the left or unimpregnated uterine horn, and subjected 

 these to the staining action of logwood, with the aid of the micro- 

 scope the presence of numerous uterine glands could be readily 

 recognised. These glands were very unequally distributed in the 

 mucous membrane. At some places they appeared to form patches, 

 and were so closely packed that the interval separating any two 

 of them did not exceed half the diameter of a gland tube, 

 whilst at others the individual glands were separated by a much 



