176 APPENDAGES OF THE FCETUS. 



adherent layer of a cream-like matter contained in its interior; that, 

 in the microscope, it presented a villous appearance, and that from 

 this double peculiarity it is probable that the substance in the reticu- 

 lated body is secreted by its own parietes. This, moreover, would 

 be an argument in favor of the opinion of Harvey, of Joerg, and of 

 Oken, in relation to the fluid of the allantois in animals. I will ob- 

 serve further, that this matter preserves its cream-like, flaky aspect, 

 its appearances of an emulsive fluid, its characters of a nutritive 

 substance, until the ovule is well fixed in the womb, and then disap- 

 pears very rapidly, giving place to the albuminous stratum, which 

 remains until the termination of pregnancy. I make no mention here 

 of a third vesicle described in the Jsis by M. Pockels, under the 

 title of the erythroid vesicle, because I have never noticed it, and be- 

 cause I believe the author is mistaken in relation to it. 



SECTION 3. 



Of the Cord and Placenta. 



§. I. ©1* the Uinljilical Cord {funiculus timUlicalis). 



458. The umbilical cord is a stem by which the abdomen of the 

 foetus is connected with the membranes of the ovum, from the com- 

 mencement until the end of pregnancy. 



459. Its length, although variable, is notwithstanding generally the 

 same as, or a little greater or less than that of the foetus at birth, that 

 is to say, from fifteen to twenty inches. Denman, L'Heritier, and 

 MM. Morlanne and Maygrier, have spoken of cords measuring four, 

 five, and even six feet in length; others have been seen only a few 

 inches long, which even retained the placenta in contact with the 

 foetus; but these extremes of dimension are rare, and some of the 

 notices of them require to be repeated. 



460. Some times thicker, at others more slender, it generally is 

 about the size of the little finger. In this respect its anomalies, 

 which are much more apparent than real, depend upon whether the 

 spongy tissue of which it is partly composed is engorged with fluids 

 which constitutes fat cords, or on the other hand almost entirely 

 desiccated, and then the cord is lean. However, they may also de- 

 pend upon varieties in the absolute thickness of their vessels or 

 sheaths. 



461. Although smooth and polished like the serous membranes, 

 the human cord, nevertheless, exhibits many nodosities of diflerent 

 kinds, on which I must dwell for a moment: on some occasions they 

 are real knots, either simple or complex; more frequently, however* 



