Sex Dctcrniiiititio)!- 189 



these (or otherwise) the metaboh'c rate in the egg, will 

 affect the sex of the resulting ])rogeny. 



Following these ideas, Riddle was able to control 

 the sex ratio by various means. Furthermore, he makes 

 the somewhat startling statement that sex is a quanti- 

 tative phenomenon; that is, the difference between male 

 and female is a difference in degree only. A diagram 

 (fig. 31) will illustrate the situation. It rej)re.sents a 

 graduated scale based on the physiological condition of 



High H,0 U. H,0 



Fig. 31. — Illustrating Riddle's idea of sex. Sexes differ only quanti- 

 tatively, and it is possible to find various degrees of maleness and female- 

 ness at different points along the scale. 



the egg. The egg may be at any point on the scale, and 

 the sex of the individual produced by the egg will depend 

 upon its position on the scale. An egg in any position 

 to the left of the middle results in a male and to the right 

 in a female. It should be noted that if the egg is near 

 one of the extremes the j^rogeny will be either a vcn,' 

 masculine male or a very feminine female; while if the 

 egg lies near the middle point, on one side or the other, 

 the progeny will be a male with some female character- 

 istics, or a female with some male characteristics; in 

 other words, a feminine male or a masculine female. 

 In fact Riddle was actually able to bring this about, 

 obtaining at will males with all degrees of maleness, etc. 



