162 APPENDAGES OF THE FCETUS. 



the inner surface of the calcareous shell, and which is known as the 

 membrane of the shell. Finall}'-, in the mammiferae, as well as in 

 the human species, it supports the placenta or the cotyledons, and 

 throughout the remainder of its extent is separared from the womb 

 or its horns, only by an inorganic layer of variable consistence and 

 thickness. 



B. Of the Amnios. 



In the opinion of all observers, the amnios, also designated by the 

 terms amiculum, auguelette, aurelia, charta virginea, &c., is the 

 inner membrane of the human ovum; smooth, transparent, separated 

 from the foetus by the fluid which bears the same name, it slightly 

 adheres to the chorion by means of the mucous filaments or lamellae 

 which cover its outer surface. 



423. In an abortion of from ten to twelve days, for which I am 

 indebted to the kindness of Madame Lachapelle, and which was only 

 four lines in diameter, I found inside of the chorion a small trans- 

 parent sac, on the upper part of which the microscope detected an 

 opaque corpuscle of a whitish color. Did this little sac represent 

 the amnios? Was the white point the embryo? 



In an ovule of twelve or fifteen days, presented to me by M. Ber- 

 mond of Bourdeaux, I found fixed on a part of the cavity of the cho- 

 rion a small transparent sac, about three lines long. 



In another of about three iveeks, and for which also I am indebted 

 to the extreme complaisance of M. Bermond, the amnios represented 

 a vesicle three or four lines in diameter, and was stuck, as it were, on 

 the inner surface of the chorion. 



In a fourth very perfect specimen of about twenty days, which 

 Madame Charonnet was good enough to give me in April 1825, 

 the ovule separate from the reflected coat of the anhistous mem- 

 brane, measured only eight or ten lines; the amnios, excessively 

 delicate and white, was separated from the embryo only by a space 

 of a line and a half, and after being reflected along the origin of 

 the cord, seemed to be continuous without any line of demarcation 

 with the integuments of the little foetus, which, further, was well 

 formed. 



In an ovule of about an inch in diameter aged three weeks or a 

 month, given me by Madame Le Brun, the amnios formed a little 

 sac, separated from the foetus by a moderately thick stratum of fluid, 

 and which left the greater portion of the cord exposed in the cavity 

 of the chorion. 



In an ovum received from M. Fournier, Surgeon of the Royal 

 Stables, on which, from the accounts of the woman, and the size 



