ON PARTURITION. 531 



and the bulk such that the uterus is unable to retain it, added 

 to which the quantity of excrementitious matter is so much in- 

 creased that it cannot be contained by the membranes " l 



Now it has been shown above that the uterine humours are 

 not excrementitious. Nor do the weight and bulk of the 

 foetus help us to a more probable explanation ; for the foetus 

 suspended in water weighs but slightly on the placenta or 

 uterus ; besides which some nine months' children are very 

 small, much less in fact than many foetuses of eight months, 

 nevertheless they do not abide longer in the womb. And as to 

 weight, any twins of eight months are far heavier than a single 

 nine months' child; yet they are not expelled before nine 

 months are completed. Nor do we find a better reason in 

 "want of nutriment ;" twins, and even more children, are 

 abundantly supplied with support up to the full term ; and the 

 milk which after delivery is sufficient for the nourishment of the 

 child, could equally well, if transferred to the uterus, nourish 

 the foetus there. 



I should rather attribute the birth of the child to the follow- 

 ing reason that the juices within the amnion, hitherto admi- 

 rably adapted for nutriment, at that particular period either 

 fail or become contaminated by excrementitious matter. I 

 have touched on this subject before. The variation in the term 

 of utero-gestation, occurring as it does chiefly in the human 

 species, I believe to depend on the habits of life, feebleness of 

 body, and on the various affections of the mind. And thus in 

 the case of domesticated animals, owing to their indolence and 

 overfeeding, the seasons both of copulation and production are 

 less fixed and certain than in the wilder tribes. So women in 

 robust health usually experience easy and rapid labours; the 

 contrary holding good in those whose constitutions are shat- 

 tered by disease. For the same thing befalls them that happens 

 to plants, the seeds and fruits of which come later and less 

 frequently to perfection in cold climates than in those where the 

 soil is good and the sun powerful. Thus oranges in this country 

 usually remain on the tree two years before they arrive at 

 maturity ; and figs, w r hich in Italy ripen two or three times 

 annually, scarcely come to perfection in our climate : the 



1 p. 142. 



