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season. Take the plant lice which .multiply so rapidly upon 

 the rose bushes, fruit trees, and the like, and which are known 

 to science as aphides. "During the warmth of summer, when 

 food is abundant, these insects produce parthenogenetically 

 nothing but females, while in the famines of later autumn they 

 give birth to males. In striking confirmation of this fact it 

 has been proved that in a conservatory where aphides enjoy 

 perpetual summer, the parthenogentic succession of females 

 continued to go on for four years, and stopped only when the 

 temperature was lowered and food diminished." 



In my own experiments and observations I have found 

 several things influencing sex that I have not found men- 

 tioned by the authorities. One of these is affinity. I have 

 found that where there is perfect affinity, and the birds are 

 happy and contented, the conditions are right for the produc- 

 tion of females ; but where the birds are not well mated and 

 frequent quarrels ensue the offspring are likely to be largely 

 males. Another thing is freedom from disturbance and fear. 

 Where hens are kept stirred up by the presence of strangers 

 or shifted frequently from place to place their eggs are quite 

 sure to hatch an excess of males. The quieter you can keep 

 your hens the more pullets you will get. 



The greater the number of females to a male the more 

 pullets. I know a man who mated two roosters to 118 hens, 

 and out of 135 chickens hatched 107 were females. 



Now let me sum up all that has been said in language of 

 another: "Such conditions as deficient or abnormal food, 

 low temperature, deficient light, moisture and the like, are ob- 

 viously such as would tend to induce a preponderance of 

 waste over repair a katabolic habit of body and these con- 

 ditions tend to result in the production of males. Similarly, 

 the approved set of factors, such as abundant and rich nutri- 

 tion, abundant light and moisture, favor constructive pro- 

 cesses, that is, make for an anabolic habit, and these condi- 

 tions result in the production of females. With some element 

 of uncertainty we may also include the influence of the age 

 and of physiological prime of either sex, and of the period of 

 fertilization. But the general conclusion is tolerably secure, 

 that in the determination of sex influences inducing katabol- 

 ism (or waste) tend to result in the production of males, as 

 those favoring anabolism (or repair) similarly increase the 

 probability of females." 



This is the law of sex, so far as it can be stated at present. 



