416 THE PLACENTA AND GENERATIVE 



men leaves little doubt that at least one-fourth of the girdle-like placenta of the 

 elephant consists of the hypertrophical mucous membranes of the uterus. It 

 will be seen, therefore, that the placenta of the elephant is not only interesting on 

 account of its rarity, but also from its combining the characters of the placentae 

 of three different sets of animals. The impossibility of using the placenta, in the 

 case of the elephant at least, as a means of classification is therefore sufficiently 

 obvious. As the taxonomic value of the placenta in general has been well dis- 

 cussed by Home, Owen, Milne Edwards, Huxley, and others, I will not dwell 

 further on that part of the subject, but proceed to describe the specimen before 

 me. 



The chorion (PI. 48, a, a') of the elephant is an oblong whitish sac tapering 

 rather into an obtuse end. Its length is five feet two and a half inches, width 

 two feet four inches. The outer surface of the chorion is tolerably smooth and 

 transparent. The inner surface exhibits a number of bloodvessels. The chorion 

 is encircled or girdled by the placenta (PI. 48, c). On each side of the placenta 

 there is an indistinct brownish granular layer (PI. 48, x) four inches in width 

 and about a line thick, which runs parallel with the whole circumference of the 

 placenta, and in some places even overlaps it slightly. This same granular 

 matter was found even scattered over the surface of the placenta, and was easily 

 rubbed off with the finger. Its microscopic structure reminded me of broken- 

 down granular matter, and I suspect it may be maternal in its origin. At the 

 two poles of the chorion I found the " subcircular vascular villous patches" (PI. 

 48, v) described by Prof. Owen. The villi in this position were not more than a 

 line long. The placenta entirely surrounds the chorion, but is situated at one 

 side of the middle line. Consequently, the two parts of the chorion differ in length, 

 the longer measuring thirty-five inches, the shorter twenty inches. The width of 

 the placenta is seven and a half inches, making a total length in long diameter 

 for the chorion of sixty-two and a half inches, as stated above. The circumference 

 of the placenta is five feet one inch, and on an average it is two inches thick. 

 The placenta preserves the same average width all round; there is no constriction 

 dividing it into the "two moities" described by Prof. Owen; and another differ- 

 ence is that the villous processes are as well developed at the edges of the placenta 

 as in the middle. Indeed, there is no smooth surface whatever, as seen in Prof. 

 Owen's specimen. The general appearance of the placenta was that of a brownish 

 spongy zone. After injection, however, when the vessels had been filled, the 

 red color differentiated very well the foetal from the maternal parts, which were 

 closely interlaced. The villi divided and subdivided in an arborescent manner, 



