EVOLUTION IN BIOLOGY 189 
7 | Harvey proceeds to contrast this view with that 
_ of the “ Medici,” or followers of Hippocrates and 
Galen, who, “ badly philosophising,” imagined that 
the brain, the heart, and the liver were simul- 
_ taneously first generated in the form of vesicles ; 
and, at the same time, while expressing his 
- agreement with Aristotle in the principle of epi- 
genesis, he maintains that it is the blood which is 
the primal generative part, and not, as Aristotle 
- thought, the heart. 
In the latter part of the seventeenth century, 
"the doctrine of epigenesis, thus advocated by 
Harvey, was controverted, on the ground of direct 
observation, by Malpighi, who affirmed that the 
body of the chick is to be seen in the egg, before 
the punctum sanguineum makes it appearance. 
But, from this perfectly correct observation a con- 
clusion which is by no means warranted was drawn ; 
namely, that the chick, as a whole, really exists in 
_ the egg antecedently to incubation ; and that what 
happens i in the course of the iter process is no 
. 
: 
: 
addition of new parts, “alias post alias natas,” 
Harvey puts it, but a simple expansion, or unfold. 
ing, of the organs which already exist, though they 
are too small and inconspicuous to be discovered. 
The weight of Malpighi’s observations therefore 
fell into the scale of that doctrine which Harvey 
terms metamorphosis, in contradistinction to epi- 
genesis. 
The views of Malphigi were warmly welcomed, 
