Chap. 70.] ANIMALS WHICH HAYE TWO HEAETS. 65 
loped in a membrane equally supple and strong, and is pro- 
tected by the bulwarks formed by the ribs and the bone of 
the breast, as being the primary source and origin of life. It 
contains within itself the primary receptacles for the spirit and 
the blood, in its sinuous cavity, which in the larger animals is 
threefold, ^'^ and in all twofold at least : here it is that the 
mind^^ has its abode. From this source proceed two large 
veins, which branch into the fore-part and the back of the body, 
and which, spreading out in a series of branches, convey the 
vital blood by other smaller veins over all parts of the body. 
This is the only one^^ among the viscera that is not affected by 
maladies, nor is it subject to the ordinary penalties of human 
life ; but when injured, it produces instant death. While all 
the other viscera are injured, vitality may still remain in the 
heart. 
CHAP. 70. — THOSE ANIMALS WHICH HAVE THE LAEGEST HEAET, 
AND THOSE WHICH HAVE THE SMALLEST. WHAT ANIMALS HAVE 
TWO HEAETS. 
Those animals are looked upon as stupid and lumpish which 
have a hard, rigid heart, while those in which it is small are 
courageous, and those are timid which have it very large. 
The heart is the largest, in proportion to the body, in the 
mouse, the hare, the ass, the stag, the panther, the weasel, the 
hysena, and all the animals, in fact, which are timid, or dan- 
gerous only from the effects of fear. In Paphlagonia the par- 
tridge has a double heart. In the heart of the horse and the 
ox there are bones sometimes found. It is said that the heart 
increases every year in man, and that two drachmae in weight 
are added yearly up to the fiftieth year, after which period 
it decreases yearly in a similar ratio ; and that it is for this 
reason that men do not live beyond their hundredth year, the 
heart then failing them : this is the notion entertained by the 
Egyptians, whose custom it is to embalm the bodies of the 
^"^ Among all the mammiferae and the birds, the heart has four cavities, 
two on each side. Mens. 
^9 This is a mistake. The heart is subject to disease, equally with other 
parts of the body. 
In spite of what Schenkius says in confirmation of Pliny, this is 
very doubtful. Of course it must increase from childhood, but the in- 
crease surely does not continue till the fiftieth year. 
VOL. III. F 
