234 NOVEMBER 



"Then how did you find out about the little 

 house ? " 



" I had to wait several months until its owner 

 showed itself. One day a perfectly clean section 

 was cut out of the cocoon, and a four-winged 

 bee-like insect emerged. I did not know any 



bee which was in the habit of choosing this sort 



& 



of residence for the winter, so I had to watch 

 and compare until I finally concluded that it was 

 a sawfly." 



" Then why did he look like a bee ? " 



''Thousands of years ago he began probably to 

 develop a little bit of yellow on his body, and in 

 the course of time by a process of selection he be- 

 came more and more bee-like, until now it needs 

 more than a casual glance to tell the two apart. 

 Bees have stings, and the more the sawfly resembled 

 a stinging insect the more likely he was to escape 

 his enemies. Have you ever noticed towards the 

 end of the summer an unusually large number of 

 big buzzy bees ? " 



"Of course I have." 



" Well, those big buzzy bees are nothing more 

 than two-winged flies which have gradually become 

 so like bees that their enemies birds as well as 

 men have come to leave them alone, though they 

 are as devoid of weapons as the common housefly. 

 They merely imitate the bee for their own protec- 

 tion." 



"What a joke the whole thing must be to them ! 

 Do you think they are really able to enjoy it ? Are 

 they laughing up their antennae while we pass them 

 by with a shudder ? " 



