216 THE FCETUS. 



membranes occluded, are not on that account less completely de- 

 veloped, and their alimentary canal, according to the reports of 

 certain observers, does not contain less of meconium or of hairs. 

 It does not necessarily follow from the circumstance that liquor 



amnii has been found in the stomach, that the fcetus swallows and 

 .* . . . 



is nourished by it; would it be right to infer that a swimmer natu- 

 rally drinks water, because we find some of it in the stomachs of 

 drowned persons? Finally, ought it not to be enough to decide for 

 ever the question as to the nutritive properties of the liquor amnii, 

 to observe, that Bartholin and M. Morlanne have seen the fostus 

 continue to live in the womb more than a month after the complete 

 evacuation of the waters. 



555. It is therefore superfluous to inquire whether the water of 

 the amnios, after passing into the intestines, is simply absorbed from 

 them, as was thought by La Courvee to be the case, or whether, as 

 Diemerbroeck, Boerhaave and others pretend, it must undergo a 

 previous digestion in those organs; neither is it necessary to refute 

 M. Lobstein, who is not far from making it pass in, partly, by the 

 genital organs of the foetus; nor Osiander and MuUer, who make 

 out, that it is absorbed, then modified by the breasts, to be subse- 

 quently carried to the thymus gland and thoracic duct; nor, finally, 

 Schurigius, David, Roederer, Scheele, Winslow, Heroldt, Beclard 

 and M. Geoffroy Saint-Hilaire, who believe that it penetrates into 

 the trachea and bronchia, in order to be there elaborated, or serve 

 in some way for the purposes of the foetal nutrition. 



Notwithstanding the importance attributed by some writers to the 

 water of the amnios, all the authors, except La Courvee and a few 

 others, have confessed that the placenta performs the principal part 

 in the nutrition of the foetus, at least during the latter half of the 

 period of gestation. 



There are some who, with the ancients, suppose that the placenta, 

 by means of some peculiar lymphatics, takes up a milky juice, a 

 real chyle, for the purpose of modifying or transmitting it to the 

 organs of the fcetus. 



556. Others have asserted that the placenta takes nothing from 

 the womb except the oxygen, that it performs the functions of a respi- 

 ratory organ, that it is the physiological lungs of the foetus, and that in 

 this view the uterine arteries represent, in some measure, the bronchia 

 and trachea. In a figurative sense these assertions are not wholly 

 without foundation, as I shall remark further on; but when taken in a 

 literal sense, as they have been by an infinite number of physiologists, 

 they become valueless. 



557. A majority of writers maintain that the fcetus is nourished 



