70 BEES AND POLLEN-COLLECTING 



ing for the different action of the hind legs makes 

 them just as good cleaners as the razors of the 

 front pair ; the spurs at the apex of the tibiae, 

 which are known as the calcaria, are also doubt- 

 less useful for cleaning purposes, and this is 

 specially suggested by the beautiful saw-like 

 form which they assume in some species ; al- 

 though there is no actual semicircular comb 

 in the first joint of the tarsi, yet there can be 

 little doubt that the spur and this joint in 

 conjunction can act as a cleaning organ very 

 much in the same way as the more elaborate 

 arrangement in the front legs. Any one who 

 has the opportunity of examining the hairs of 

 bees under a microscope will be amply repaid 

 for the trouble in noticing the beautiful shapes 

 and structures which these organs assume. 

 (Figs. 13-18 ; 17 showing pollen grains adhering.) 

 At one time, when I was specially examining 

 bee hairs, I shaved the various parts of a large 

 number of species and mounted their hairs dry 

 in microscopic slides, merely securing the cover 

 glass with liquid glue ; this was twenty years 

 ago, and many are still quite good. It may 

 seem a difficult operation to shave a bee, but 



