346 



riddle: control of sex ratio 



might have been predicted to result as these three investigators 

 have reported. 



The modified sex ratios obtained from the four types of ani- 

 mals just mentioned were all obtained through action upon the 

 eggs, or the egg-stage of the organisms. Some important ex- 

 perimental work, and other very significant physiological and 

 chemical study, has been done on sex in the embryonic and adult 



CHART 2 



Bonellia; Free-martin; Inachus; Frog; Pigeon; Duck; Fowl; Pheasant; Sheep; 



Human; Stag. 



Cow 



Egg ■ 



[ cfhigh per cent H 2 (?) 

 9 low per cent (H 2 (?) 



Pigeon \ ■ 



Frog 

 Toad 



Hydatina 



Daphnids 



Moths 



flow fat and P. 

 cf \ High Metabolism 

 [high per cent H2O 



(high fat and P. 

 9 \ Low Metabolism 

 [low per cent H2O 



cf high per cent H2O 

 9 low per cent H2O 



-+Adult • 



Human • 



Fowl 



Crab 



[ (blood) low per cent 



fat 

 High Metabolism 



f (blood) high per cent 

 9 I fat 



[Low Metabolism 



c? (blood) low fat and P. 

 9 (blood) high fat and P. 



cf (blqod) low per cent fat 

 9 (blood) high per cent fat 



cf's from change of food and increased oxygen supply. 

 9 's from unchanged food and lesser oxygen supply. 



sex-intermediates — sexual or asexual reproduction influenced by 

 conditions. 



sex-intermediates — quantitative germinal basis. 



stages of the organism. Something can here be gained by 

 grouping and treating these several results in a single diagram. 

 Now that the basic problem of sex has been shown to be essen- 

 tially a question of metabolism, a department of physiology and 

 biochemistry, we shall be able to note in connection with Chart 

 2 (where the principal known facts concerning the relation of 

 metabolism to sex are diagrammatically arranged) that a num- 



