214 THE FCETUS. 



matter, has no more to do with it than the caduca, and it is not true 

 that it becomes less abundant in quantity as the foetus grows larger. 



The idea of making the foetus live upon the fluid with which it is 

 surrounded, is the most ancient of all, and apparemly the most na- 

 tural; it gives rise to two very distinct theories; by one the water of 

 the amnios is supposed to be swallowed and digested; according to 

 the other it is absorbed in various ways. 



551. In order to prove that the water of the amnios serves for the 

 nourishment of the foetus, the old writers, particularly Harvey and 

 Diemerbroeck, have treated at great length on its nutritous qualities, 

 and on the lactescent matter which in their opinion it always con- 

 tains; later authors have relied upon the assertion that small animals 

 plunged in it live longer than they do when plunged in common 

 ■water; on its being more abundant and fuller of nutritive principles, 

 in proportion as pregnancy is less advanced; on the diminished 

 power of absorption in the cutaneous surface of the foetus, as it ap- 

 proaches nearer to the full term; and on certain cases of foetuses 

 being born alive without any umbilical cord. 



552. Without stopping to refute these various propositions one 

 by one, it may be remarked that previously to drawing practical con- 

 sequences from them, their correctness should have been ascertained; 

 but it has never been proved that the liquor amnii is more nutritious 

 at the beginning than at the close of pregnancy; or that the foetus 

 absorbs more at one time than another. As to the observations of 

 Van-der-wiell, of Dennis and Littre, on the absence of the umbilical 

 cord, and on the rupture and cicatrisation of its divided extremities, 

 they are too improbable, and accompanied with details far too vague 

 for them to deserve the least credit. 



Nothing, positively nothing, warrants our believing with Alcmaeon, 

 Boerhave, Buff'on, and Van-den-Bosch, that the waters are taken 

 up by the cutaneous surface. The last author, it is true, tells us he 

 saw the lymphatic vessels full of a fluid resembling the water of the 

 amnios, and that they became fuller in the limb of a cow's fcBtus, 

 strongly bound round with a ligature and plunged in the liquor of 

 the membranes; but even admitting the experiment to be correct, 

 what conclusion can we draw from it? Are not the lymphatic ves- 

 sels habitually filled with serosity? Do they ever fail to become 

 distended when a mechanical obstruction prevents the free passage 

 of the blood through a part, or the whole of a limb? 



553. Founding on the opinion of Hippocrates, of Harvey, Rud- 

 beck, (fcc, and on some facts of his own, Diemerbroeck maintains 

 that the fostus is nourished by the mouth. His reasons are, that the 



