More Hunting Wasps 



Bees and Wasps, indeed, the male and the 

 female differ not only in certain details of 

 internal or external structure — a point of 

 view which does not affect the present pro- 

 blem — but also in length and bulk, which de- 

 pend in a high degree on the quantity of food. 



Let us consider in particular the Bee-eat- 

 ing Philanthus. Compared with the female, 

 the male Is a mere abortion. I find that he Is 

 only a third to half the size of the other 

 sex, as far as I can judge by sight alone. To 

 obtain exactly the respective quantities of 

 substance, I should need delicate balances, 

 capable of weighing down to a milligramme. 

 My clumsy villager's scales, on which po- 

 tatoes may be weighed to within a kilo- 

 gramme or so, do not permit of this pre- 

 cision. I must therefore rely on the evi- 

 dence of my sight alone, evidence, for that 

 matter, which is amply sufficient In the pre- 

 sent instance. Compared with his mate, the 

 Mantis-hunting Tachytes is likewise a pigmy. 

 We are quite astonished to see him pester- 

 ing his giantess on the threshold of the bur- 

 rows. 



We observe differences no less pronounced 

 of size — and consequently of volume, mass 

 and weight — In the two sexes of many Os- 

 miae. The differences are less emphatic, but 



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