Life-energy must be present in all living bodies in the forms, respectively, of _latent_ Vital Energy and _functioning_ Vital Energy--energy conserved and available for functioning, and energy expending itself in the living processes of mentality and action. An individual is able to move his limbs by power of the _potential_ motion stored, or latent, in the muscle-cells of his limbs. Just as a locomotive-engine is enabled to travel by power of the _potential_ motion stored in the steam generated in its boiler. And as in the living organism, so in the engine, the mechanism and the processes that engender in it the _potential motion_ of steam are wholly distinct from those which convert this potential motion into _actual motion_. One is able to think, by power of the _potential_ mentality stored, or latent, in his brain-cells. For not only the vital processes which sustain the life of the organism, as those too which enable it to function in terms of living personality and action, but brain-power also must exist in the dual forms, respectively, of _potential_ Faculty and _functioning_ Faculty. So too, Reproductive power. In all of these appear again the modes of Dominance and Recessiveness, of powers _positive_ and _manifesting_, and of powers _negative_ and _latent_. And since the female sex is characterised by traits of repose and conservation, and the male sex by traits of action, the dual modes of vital, muscular, cerebral and reproductive energy _in potential_, and of vital, muscular, cerebral and reproductive energy _in course of generating function_, range themselves inevitably on the two sides of the living equation as Sex-characteristics differentiating the male organisation from that of the female. Thus ranged, they characterise the two sides of the body as representing, respectively, a right, male side which is the central agency in function, and a left, female side, which is the reservoir of the _potential_ of function. If then the female mode of functioning is the Potential, or Recessive, a mode of latency, it is to be inferred that the male traits every female creature inherits from her father will, when incorporated in a body of female prepotence, pass into the potential, or Recessive, mode; and will thus become inhibited from developing as male-characteristics. Nevertheless, this male potential will be preserved in that reproductive gland which represents the paternal inherences in her, and will be transmitted, as her contribution to male offspring, in the sex-cells generated by this gland. While the female inherences every male derives from his mother will, in the presence of the Dominant male-characteristics he derives from his father, retain their latent, or Recessive, mode; and will thus not emerge as female characteristics. The female inherences will be preserved, however, in that reproductive gland which represents the maternal inherences in him; and will be transmitted as his contribution to female offspring.