98 THE MICKOSCOPE AND ITS LESSONS. 



Kernember, a spider is not an insect: first, it is 

 utterly destitute of wings ; secondly, it never undergoes 

 any transformation ; thirdly, the head is not separated 

 from the thorax as those of insects are, but is united to 

 it, there being only two great divisions of the w r hole 

 body, instead of three; fourthly, the eyes, which are 

 generally eight, are of a totally different character to 

 those of insects, which are often compound. In the 

 dragon-fly, for example, we are told by a competent 

 author,* there are no less than 36,000 separate lenses, 

 measuring a little more than only a thousandth part of 

 an inch in diameter, each being really a separate and 

 distinct organ, with its own crystalline lens in front and 

 microscopic telescope behind, running back to the retina. 

 But, having given a pictorial description of this in another 

 place, I need not do more here than remind you of the 

 difference of structure and number between a spider's 

 simple eye and that of an insect ; perhaps, as we get 

 further on in our story, we may come across the truly 

 wonderful eyes of some spiders, which will astonish yon 

 by the perfection of their workmanship, and you will 

 exclaim something more pleasing than did a very raw 

 countrymen to one, to whom I am indebted for many 

 interesting facts in natural history, who, while exhibiting 

 parts of insects, just as I am now supposed to be doing 

 to you, heard him exclaim, "Lor, don't they get 'em fine 

 in Lunnon, eh ? " 



How very different to the exclamation of a poor 

 African slave-boy, who, falling into the hands of our 

 sailors a few months ago while our war-ships, acting in 

 conjunction with Germany, were off the coast of Zanzibar, 

 when rescued and received on board one of our big 

 steamers, as he was led from one part to another, was 

 * Henry Walker, F.G.S., in the Leisure Hour, April, 188G. 



