Rationing According to Sex 



It is unnecessary to linger longer over this 

 subject. The demonstration is completed. 

 The parasites tell us that changes in the 

 quantity and quality of food do not lead to 

 any transformation of species. Fed upon 

 the larva of the Three-horned Osmla or of 

 the Blue Osmla, Anthrax sinuata, whether of 

 handsome proportions or a dwarf, Is still 

 Anthrax sinuata; fed upon the allowance of 

 the Anthldlum of the empty Snail-shells, the 

 Anthldlum of the brambles, the Megachlle 

 or doubtless many others, the Burnt Zonitis 

 is still the Burnt Zonltls. Yet variation of 

 diet ought to be a very potential factor In 

 the problem of progress towards another 

 form. Is not the world of living creatures 

 ruled by the stomach? And the value of this 

 factor is unity, changing nothing in the pro- 

 duct. 



The same parasites tell us — and this is 

 the chief object of my digression — that ex- 

 cess or deficiency of nutriment does not de- 

 termine the sex. So we are once more con- 

 fronted with the strange proposition, which 

 is now more positive than ever, that the in- 

 sect which amasses provisions in proportion 

 to the needs of the egg about to be laid 

 knows beforehand what the sex of this egg 

 will be. Perhaps the reality is even more 

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