The Mason-bees 



to be done on the spot selected for the 

 starting-point. I use finely-powdered chalk, 

 steeped in a strong solution of gum arable. 

 The mixture, applied to some part of the in- 

 sect with a straw, leaves a white patch, which 

 soon dries and adheres to the fleece. When 

 a particular Mason-bee has to be marked so 

 as to distinguish her from another in short 

 experiments, such as I shall describe presently, 

 I confine myself to touching the tip of the 

 abdomen with my straw while the insect is 

 half in the cell, head downwards. The slight 

 touch is not noticed by the Bee, who continues 

 her work quite undisturbed; but the mark is 

 not very deep and moreover it Is in a rather 

 bad place for any prolonged experiment, for 

 the Bee is constantly brushing her belly to de- 

 tach the pollen and is sure to rub It off sooner 

 or later. I therefore make another one, drop- 

 ing the sticky chalk right in the middle of the 

 thorax, between the wings. 



It is hardly possible to wear gloves at this 

 work: the fingers need all their deftness to 

 take up the restless Bee delicately and to over- 

 power her without rough pressure. It Is 

 easily seen that, though the job may yield no 

 other profit, you are at least sure of being 

 42 



