infant seem most unsatisfactory in the light of these facts. If the child is observed to possess a male organ, even although there may be complete epi- or hypo-spadism, or a double failure of descent of the testes, it is at once described as a boy and is henceforth treated as one, although in other parts of the body, for instance in the brain, the sexual determinant may be much nearer thelyplasm than arrhenoplasm. The sooner a more exact method of sex discrimination is insisted upon the better.
As a result of these long inductions and deductions we may rest assured that all the cells possess a definite primary sexual determinant which must not be assumed to be alike or nearly alike throughout the same body. Every cell, every cell-complex, and every organ have their distinctive indices on the scale between thelyplasm and arrhenoplasm. For the exact definition of the sex, an estimation of the indices over the whole body would be necessary. I should be content to bear the blame of all the theoretical and practical errors in this book did I believe myself to have made the working out of a single case possible.
Differences in the primary sexual determinants, together with the varying internal secretions (which differ in quantity and quality in different individuals) produce the phenomena of sexually intermediate forms. Arrhenoplasm and thelyplasm, in their countless modifications, are the microscopic agencies which, in co-operation with the internal secretions, give rise to the macroscopic differences cited in the last chapter.
If the correctness of the conclusions so far stated may be assumed, the necessity is at once evident for a whole series of anatomical, physiological, histological and histo-chemical investigations into those differences between male and female types, in the structure and function of the individual organs by which the dowers of arrhenoplasm and thelyplasm express themselves in the tissues. The knowledge we possess at the present time on these matters comes from the study of averages, but averages fail to satisfy the modern statistician, and their scientific value is very small. Investigations into
