Bramble-bees and Others 



snares, or whether she makes a mistake in 

 considering only the space at her disposal 

 and beginning with males. At any rate, 

 I perceive in her a tendency to deviate 

 as little as possible from the order which safe- 

 guards the emergence of the two sexes. This 

 tendency is demonstrated by her repugnance 

 to colonizing my narrow tubes with long 

 series of males. However, so far as we are 

 concerned, it does not matter much what 

 passes at such times in the Osmia's little brain. 

 Enough for us to know that she dislikes nar- 

 row and long tubes, not because they are nar- 

 row, but because they are at the same time 

 long. 



And, in fact, she does very well with a 

 short tube of the same diameter. Such are 

 the cells in the old nests of the Mason-bee of 

 the Shrubs and the empty shells of the Gar- 

 den Snail. With the short tube, the two dis- 

 advantages of the long tube are avoided. She 

 has very little of that crawling backwards to 

 do when she has a Snail-shell for the home 

 of her eggs and scarcely any when the home 

 is the cell of the Mason-bee. Moreover, as 

 the stack of cocoons numbers two or three at 

 most, the deliverance will be exempt from the 



170 



