More Enquiries into Mason-bees 



perfect magnet : it attracts and repels another 

 magnetized needle hanging from a thread. 

 I am a little puzzled as to the best way to 

 fasten it on the insect's thorax. My assistant 

 of the moment, the pharmaceutical student, 

 requisitions all the adhesives in his labora- 

 tory. The best is a sort of cerecloth which 

 he prepares specially with a very fine mate- 

 rial. It possesses the advantage that it can 

 be softened at the bowl of one's pipe when the 

 time comes to operate out of doors. 



I cut out of this cerecloth a small square 

 the size of the Bee's thorax; and I insert the 

 magnetized point through a few threads of 

 the material. All that we now have to do is 

 to soften the gum a little and then dab the 

 thing at once on the Mason-bee's back, so 

 that the broken needle runs parallel with the 

 spine. Other engines of the same kind are 

 prepared and due note taken of their poles, 

 so as to enable me to point the south pole at 

 the insect's head in some cases and at the op- 

 posite end In others. 



My assistant and I began by rehearsing the 



performance; we must have a little practice 



before trying the experiment away from 



home. Besides, I want to see how the insect 



los 



