The Mason-bees 



insect, would affect It more than would the 

 terrestrial currents." 



There is still the same idea of turning the 

 insect into a sort of bar magnet. The ter- 

 restrial currents guide it when returning to 

 the nest. It becomes a living compass which, 

 withdrawn from the action of the earth by 

 the proximity of a loadstone, loses its sense of 

 direction. With a tiny magnet fastened on 

 its thorax, parallel with the nervous system 

 and more powerful than the terrestrial mag- 

 netism by reason of its comparative nearness, 

 the insect will lose its bearings. Naturally, 

 in setting down these lines, I take shelter be- 

 hind the mighty reputation of the learned be- 

 getter of the idea. It v/ould not be accepted 

 as serious coming from a humble person like 

 myself. Obscurity cannot afford these auda- 

 cious theories. 



The experiment seems easy; it is not be- 

 yond the means at my disposal. Let us at- 

 tempt it. I magnetize a very fine needle by 

 rubbing it with my bar magnet; I retain only 

 the slenderest part, the point, some five or 

 six millimetres long.^ This broken piece is a 



*.2 to .23 inch. — Translator's Note. 

 104 



