Psychology of sex - Total No. of Records in System :: 2032

THE BIOLOGY OF SEXbearing, or Y-bearing, while the female elaborates butone. An X-bearing egg can be fertilized either by anX-bearing sperm, to become XX and female, or a Y-bearingsperm to become XY and male. Therewith we havethe starting-point of the whole process (made clear by theextended and comprehensive investigations of Evans andSwezy) which there is no occasion to follow in detail herein its variations along, as is now held, Mendelian lines.The Mendelian processes of heredity are much morevaried and complicated in man than in those lower organismsin which they were first studied.We have to conclude that sex isnormally determined atconception, and to put aside all the various devices fordetermining sex during pregnancy. It is certainly necessaryto postulate, in Crew's words, that "in every zygote,be it XX or XY in sex chromosome constitution, thereare the physical bases of developmental impulses whichstrive to impose upon the developing individual a maletype and a female type of differentiation respectively."It is necessary to refer to the recent developments ofknowledge in this field recent as belonging to thepresent century because they happen to be of peculiarlyclose relationship to the psychology of sex.At the outset we assume as accepted that when a complexof glands to which the testes is central predominatesin the organism we have an individual of male sex; whena complex of glands to which the ovary is central predominateswe have a female. Thus are secured normallythe primary sexual characters. Associated with them is thedevelopment of the respective sexual organs. Finallysexual maturity is established with the full acquisition ofthe manifest secondary characters, with which are associated,as tertiary sexual characters, many differenceswhich are not obvious. All these processesare liable to[ 9]