378. 13. Jealousness is found also in animals and birds. People know that it is found in wild animals, such as lions, tigers, bears, and others, when they have their young. So, too, in bulls, even though they do not have calves.
It is very apparent in cocks, which battle with rivals over their hens, even to their death. They are possessed of such jealousness, because they are vainglorious lovers, and the vainglory of their love does not tolerate a rival. One can see that they are vainglorious lovers - more vainglorious than any other kind or species of bird - from their movements, the motions of their heads, their struttings, and the sounds they make.
We have already shown above in the case of men, that whether they feel any love or not, the vainglory of their honor induces, heightens, and exacerbates jealousness.
