The Mason-bees 



"They certainly know me." 



"And me?" 



"Oh, you : that's another matter !" 



Whereupon the intruder would keep at a 

 respectful distance, which was what I wanted. 



It is time that we thought of experiment- 

 ing. The Mason-bees intended for the jour- 

 ney must be marked with a sign whereby I 

 may know them. A solution of gum arabic, 

 thickened with a colouring-powder, red, blue 

 or some other shade, is the material which I 

 use to mark my travellers. The variety in 

 hue will save me from confusing the subjects 

 of my different experiments. 



When making my former investigations, I 

 used to mark the Bees at the place where I 

 set them free. For this operation, the in- 

 sects had to be held in the fingers one after 

 the other; and I v/as thus exposed to frequent 

 stings, v/hich smarted all the more for being 

 constantly repeated. The consequence was 

 that I was not always quite able to control 

 my fingers and thumbs, to the great detriment 

 of my travellers ; for I could easily warp their 

 wing-joints and thus weaken their flight. It 

 was worth while improving the method of 

 operation, both in my own interest and in that 



