488 PROFESSOR TURNER ON THE GRAVID UTERUS AND 



multitudes of elongated feeble ridgelets traversed the surface of the chorion, 

 which fitted into corresponding shallow elongated depressions in the uterine 

 mucous membrane, but no true villi were recognised, and the smooth and feebly 

 vascular poles were absolutely and relatively larger than in the cetacean. A 

 distinct and compact capillary plexus, which was injected with carmine and 

 gelatine, was seen both in the ridgelets and in the intermediate portions of the 

 chorion. This plexus was elongated within the ridgelets, and had the same 

 direction, but in the intermediate membrane it formed a polygonal network, so 

 that the entire surface of the chorion, except at the poles, possessed a diffused 

 capillary vascularity, without any differentiation into intra- and extra-villous 

 areas of distribution. 



In possessing a basis substance of delicate connective tissue, in which nume- 

 rous nucleated corpuscles lie, the chorionic villi in the cetacean agreed with the 

 structure of villi generally. The layer of corpuscles situated immediately within 

 the periphery of the villus, which I have described as its sub-epithelial corpuscles 

 (p. 479), obviously corresponds in position, arrangement, and shape, to the 

 corpuscles figured and described as the internal cells of the villus,""" by Pro- 

 fessor Goodsir in the villi of the human chorion. In a recently published and 

 very elaborate memoir on the " Structure and Function of the Placenta," 

 Professor Ercolani of Bologna has also figured,! in connection with the human 

 villij a layer of spheroidal corpuscles, which he terms the cells of the internal 

 epithelial layer, situated to all appearance within the villus close to the foetal 

 vessel, for he represents a layer of membrane immediately outside the cells. His 

 drawing certainly gives one the impression that these cells corresponded in 

 position with the sub- epithelial corpuscles above referred to, but in his text he 

 speaks of them as not included in the thickness of the membrane, but as cells 

 of the decidua serotina which enter into the formation of a new glandular 

 organ which envelopes the villus. Moreover, he regards them as identical with 

 the single layer of flattened spheroidal cells which Dr FarreJ observed and 

 described as forming the sheath or outer case of the villus, and which undoubt- 

 edly belonged to the decidua serotina, and not to the chorionic villi. Although, 

 for the reasons already stated, I did not detect an epithelial layer on the free 

 surface of the villi, yet it is probable that not only they, but the whole outer 

 surface of the chorion, possessed an epithelial covering, as is the case with the 

 chorion in other mammals. 



Passing now to the consideration of the characters of the uterine mucous 



* Anatomical and Pathological Observations, p. 54, plate 2, fig. 19, f. 1845, reproduced in Ana- 

 tomical Memoirs, vol. ii. p. 18. Edinburgh, 1868. 



t Memoire sur les glandes utriculaires de l'uterus, et sur l'organe glandulaire de neo-formation, &c. 

 I know this work, which was published at Bologna in 1868, only in the Erench Translation by Bruch 

 and Andreini. Algier, 1869. Plate X. fig. 2, b. 



+ Cyclop, of Anat. and Phys., article Uterus, p. 718, fig. 485. 



