The brain of man, like that of all animals is double, being parted down its centre by a thin membrane. For this reason pain is not always felt in the same part of the head, but sometimes on one side, sometimes on the other, and occasionally all over.
HippocratesMale and female have the power to fuse into one solid, both because both are nourished in both and also because soul is the same thing in all living creatures, although the body of each is different.
Hippocrates