ON GENERATION. 255 



the body. This viscus indeed was so highly dignified that it 

 was thought to be produced in the very beginning, and simul- 

 taneously with the heart, from the seminal fluid of the mother ; 

 and the medical fable of the three vesicles or three kids, as they 

 were called, was eagerly defended. Among the number of modern 

 abettors of such views, Parisanus has of late with confidence 

 enough, but little skill, been singing to the old measure. These 

 good people do not consider that the vesicles are in motion in 

 the egg, that the heart is palpitating and the blood present and 

 perfectly concocted, before any sign or vestige of the liver ap- 

 pears. The blood is much rather to be accounted the efficient 

 cause of the liver, than this the author of the blood : for the 

 liver is engendered after the blood, and from it, being adnate 

 to the vessels that contain it. 



But neither can I agree with the Aristotelians, who maintain 

 that the heart is the author of the blood; for its parenchyma 

 or proper substance arises some little time after the blood, and 

 is superadded to the pulsating vesicles. I am, however, in much 

 doubt as to whether the pulsating vesicle or point, or the blood 

 itself be the older ; whether it be the fluid contained, or the 

 containing sacs. It is obvious, nevertheless, that that which 

 contains is formed for the sake of that which is contained, and 

 is, therefore, made later. And this much, upon the faithful 

 testimony of our eyes, is certain, that the first particle and 

 prime basis of the body are the veins, to which all the other 

 parts are posthumous and superadded. But upon this point 

 we shall say more by and by. 



Meantime we may be permitted to smile at that factitious 

 division of the parts into spermatic and sanguineous ; as if any 

 part were produced immediately from the seminal fluid, and all 

 did not spring from the same source ! 



I return to our subject. The colliquament now extends over 

 more than half the egg. The heart, hanging outwards, is at 

 some short distance from the body. And if you look attentively 

 you may perceive some of the umbilical vessels pulsating. 



