On the Respiration of the Foetus^ etc. 213 



With regard, then, to the respiration of the foetus in 

 the womb, we may suppose that the seminal juice 

 which exudes from the membranes of the uterus, or 

 from its caruncles, not only supplies nutriment to the 

 child but also makes up for the want of respiration. 

 And indeed it is probable that the umbilical arteries 

 are formed principally and perhaps exclusively for the 

 sake of respiration. Indeed I know no other purpose 

 for which they should be fashioned by Nature in every 

 foetus with such wonderful care and skill. I am 

 aware of the diversity of opinion that exists among 

 authors as to the functions of the umbilical arteries, 

 but I do not know whether among the numerous 

 offices hitherto assigned to them their true and 

 peculiar office is to be found. 



According to Adrian SpigeHus, the umbilical 

 arteries convey the blood from the foetus to the 

 exterior parts, that is, to the secundince^ for their 

 nourishment. But in fact it is evident if we look at 

 a hatched ^gg that the membranes (which in the &gg 

 correspond to the secimdince) are formed while the 

 umbilical arteries are not yet indicated, from which 

 we may infer that the said arteries are not formed for 

 the sake of the membranes. Besides, the umbilical 

 arteries are so notable in the egg at the very 

 beginning of life, and their offshoots are connected in 

 so wonderful a network, that there can be no doubt 

 that they contribute, in no small degree, to the 

 formation of the foetus and to the starting of the 

 dance of life. To this I add further that the 

 secundince are sometimes in excellent condition 

 although the foetus is quite corrupt, which is indeed 

 a very probable indication that the secimdince draw 

 nutriment rather from the mother than from the 

 foetus. 



