120 VASCULAR SYSTEM. 



Q. How is the pulse sympathetically affected ? 

 /?. Always through the heart. 



Of the Vascular System of Red Blood in different 



tfges. 



Q. How does the foramen ovale close? 



ft. By the gradual approach of the concave surfaces of 

 the two crescentic productions forming the foramen ovale, 

 and which unite and decussate at birth, closing the aper- 

 ture. 



Q. What closes the ductus arteriosus? 



t/?. It closes as the pulmonary artery dilates. 



Q. Is there red and black blood in the foetus, as in in- 

 dependent life? 



.#. There is not; all the foetal blood is black. 



Q. What investigations have proved the black colour of 

 the foetal blood? 



#. Animals have been opened, and the blood of the 

 young examined, and it has proved to be black : the blood 

 of the umbilical arteries is black; the blood of the foetus 

 dead in the mother is always black ; this last is a delusive 

 circumstance. 



Q. Does it follow that the venous blood of the adult, 

 and black blood of the foetus are similar in qualities, be- 

 cause they are so in colour? 



.#. It does not thus obtain. Foetal blood is unctuous in 

 its feel; it does not coagulate in the dead body; it has no 

 fibrin; it does not take the vermilion colour from the 

 air; it has no phosphoric salts. 



Q. How did Sabatier divide the mass of foetal blood? 



#. In two circulations; the first is thus laid down: 



