Male and Female

Dr. A. Alich, of Paris, is the latest biologist to attempt a solution to the riddle of sex determination, which has attracted inquisitive minds since antiquity. The hope of using such knowledge consciously to control the sex of offspring for practical breeding purposes as well as sentiment, has perhaps moved them most. But while few geneticists are willing to make any predictions about such possibilities, many foremost investigators are working to reveal the actual mechanics of the sex causation process. Not less than 500 theories--the majority fanciful old wives' tales based on no laboratory investigation of living material--have been recorded in literature. The most popular of these theories have had to do with: 1) the relative vigor of the parents, the more vigorous giving his or her sex to the offspring; 2) the position of the ovaries, eggs originating from the right ovary producing males, those from the left, females; 3) the state of nutrition of the ovum, a high degree of nourishment in the mother producing female offspring, and vice versa. This last might be an explanation for the well known birth of more boys than girls following wars and famines, which is now, however, believed to be due to other causes. But all of these notions are discredited now, with the possible exception of some phases of the nutritional theory.

The dominant view among biologists today, backed by much exact microscopic research into the composition of cells, in the laboratories of such men as Profs. Clarence MeClung, of the University of Pennsylvania, Michael F. Guyer, of the University of Wisconsin, and T. H. Morgan and Edmund B. Wilson, of Columbia, rests on strictly objective data. They say there is a special chromosome (chromosomes are minute bodies of constant number and appearance for each species of plant or animal which appear in the cells during cell-division) called the X--or accessory chromosome, which is found in half the spermatozoa of male animals. This is present in addition to the regular number of chromosomes, which always occur in pairs (48 in man), thus giving rise to an uneven number. Ova, on the other hand, in variably have two X-chromosomes. Eggs fertilized by spermatozoa con taining the X-element (thus giving the product a double dose of X's) become females, and the others, males. All experimentalists agree that sex is determined at the very beginning of development in the embryo.

Alich's theory is somewhat supplemental to the established one, and his data have been submitted to the French Academy. He objects to the idea that the origin of sex differences is to be found in differences in the male cells only, and claims that both the spermatozoon and the ovum have activating " microcellules." These seek their complement in the other sex cell, but if the male micro-cellules preponderate in number over the female the result will be a male embryo, and vice versa. But Alich also believes that various other factors affect this potential energy of the germ cell, including potency, fatigue, old age, and has evidence for this from horses, sheep and roosters. Dr. James W. Mavor, of Union College, has discovered that X-rays can eliminate the X-chromosome in the eggs of the fruit fly Drosiphila, upsetting the balance between the sexes of the offspring.

The whole question is decidedly in flux and new data are constantly being discovered.