G. HIND ON MOUNTING SPIDER's WEBS. 1 1 



that portion of the web that you wished to secure tightly stretched 

 upon the frame, which can now be placed in the racked box, and 

 thus kept until you are ready to examine and mount any portion of 

 it. Any insects that you may find can be thoroughly dried before 

 they are mounted. 



" In order to mount any portion of the web thus obtained, first 

 cement a thin paper cell upon a glass slip. Then having slightly 

 gummed the cell, place one of the wire frames over it, taking care 

 to bring that portion of the web that you desire to secure exactly 

 in the centre. Having done this, with the scissors remove the 

 superfluous web, and place another paper cell upon the first one, and 

 a thin glass cover over all, securing the cover with a little gum. 



** In order to keep the preparations as dry as possible, metal cells 

 might perhaps be preferable to paper ones. 



" The webs sometimes contain insects so small that they are diffi- 

 cult to find in any other way, and these, too, in a very perfect state, 

 as they are seldom touched by the spider. 



" The web itself is not devoid of interest. The radial threads 

 are continuous, whilst those which form its concentric circles are 

 beautifully beaded. Some time back I obtained several spiders in 

 order to get some good clean threads for mounting, but could not 

 succeed in inducing them to spin in confinement. I was told that I 

 did not exercise sufficient patience, and that if the spider is well 

 nourished when placed in confinement, it will often be several weeks 

 before commencing to spin. As I was not disposed to wait all this 

 time, I used occasionally to shake the spider to make it spin stray 

 threads. In doing this, I discovered the reason why the web is 

 plain in some parts and beaded in others. 



" When emitted by the spider, the web is in a very viscid state, 

 and I noticed that when the whole weight of the spider was upon 

 the web, and the thread was fastened off quickly, it was not beaded ; 

 but when by some chance the spider had slightly relaxed the tension 

 before fastening it off, I observed a slight quiver pass through the 

 thread, and upon examining it with a magnifier, I found that it was 

 beaded from end to end." 



The author concluded with a few remarks upon the value of the 

 thread of the spider for the formation of micrometers for astro- 

 nomical and surveying telescopes, and upon the methods used to 

 obtain and to prepare it for these purposes. 



