Carlyle and the Saint Simonians; the concept of historical periodicity.

Just as the sex glands influence the body and mind profoundly with a certain cyclic periodicity of activity and inactivity (rut, heat, menstrual period and so on), which has been demonstrated to have a very close functional relationship with the pituitary, so sleep and hibernation will bear interpretation as products of a temporary dormancy of the same gland.

This explosive periodicity of the sexual life, "with a tendency to compression of it to the merely physical," is another mark of some pituitary-centered personalities.