involution of the glands.  The precocious appearance of the sexual impulse in childhood he would explain as due to an anomaly of development in the sexual organs.  Fere makes no attempt to explain the presence of the sexual impulse in the congenital absence of the sexual glands; here, however, Munde intervenes with the suggestion that it is possible that in most cases “an infinitesimal trace of ovary” may exist, and preserve femininity, though insufficient to produce ovulation or menstruation.

It is proper to mention these ingenious arguments.  They are, however, purely hypothetical, obviously invented to support a theory.  It can scarcely be said that they carry conviction.  We may rather agree with Guinard that so great is the importance of reproduction that nature has multiplied the means by which preparation is made for the conjunction of the sexes and the roads by which sexual excitation may arrive.  As Hirschfeld puts it, in a discussion of this subject (Sexual-Probleme, Feb., 1912), “Nature has several irons in the fire.”

It will be seen that the conclusions we have reached indirectly involve the assumption that the spinal nervous centers, through which the sexual mechanism operates, are not sufficient to account for the whole of the phenomena of the sexual impulse.  The nervous circuit tends to involve a cerebral element, which may sometimes be of dominant importance.  Various investigators, from the time of Gall onward, have attempted to localize the sexual instinct centrally.  Such attempts, however, cannot be said to have succeeded, although they tend to show that there is a real connection between the brain and the generative organs.  Thus Ceni, of Modena, by experiments on chickens, claims to have proved the influence of the cortical centers of procreation on the faculty of generation, for he found that lesions of the cortex led to sterility corresponding in degree to the lesion; but as these results followed even independently of any disturbance of the sexual instinct, their significance is not altogether clear (Carlo Ceni, “L’Influenza dei Centri Corticali sui Fenomeni della Generazione,” Revista Sperimentale di Freniatria, 1907, fasc. 2-3).  At present, as Obici and Marchesini have well remarked, all that we can do is to assume the existence of cerebral as well as spinal sexual centers; a cerebral sexual center, in the strictest sense, remains purely hypothetical.

Although Gall’s attempt to locate the sexual instinct in the cerebellum—­well supported as it was by observations—­is no longer considered to be tenable, his discussion of the sexual instinct was of great value, far in advance of his time, and accompanied by a mass of facts gathered from many fields.  He maintained that the sexual instinct is a function of the brain, not of the sexual organs.  He combated the view ruling in his day that the seat of erotic mania must be sought in the sexual organs.