The Life of the Fly 



and twenty-six; with the Mason-bee of the 

 Sheds, between five and thlrty-slx; with the 

 Three-horned Osmla, who supplied me with 

 the largest number of records, between seven 

 and twenty-five; with the Blue Osmia {Osmia 

 cyanea, KiRB.), between five and six; with 

 the Stelis {Stelis nasiita) ^ between four and 

 twelve. 



The first return and the last two seem to 

 point to some relation between the abun- 

 dance of provisions and the number of con- 

 sumers. When the mother comes upon the 

 bountiful larva of the Masked Anthophora, 

 she gives it half-a-hundred to feed; with the 

 Stelis and the Blue Osmia, niggardly rations 

 both, she contents herself with half-a-dozen. 

 To introduce into the dining-room only the 

 number of boarders that the bill of fare will 

 allow would certainly be a most deserving per- 

 formance, especially as the insect is placed 

 under very diflicult conditions to judge the 

 contents of the cell. These contents, which lie 

 hidden under the ceiling, are invisible; and the 

 insect can derive its information only from 

 the outside of the nest, which varies in the 

 different species. We should therefore have 

 to admit the existence of a particular power 

 of discrimination, a sort of discernment of the 

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