70 THE MICROSCOPE AND ITS LESSONS. 



I will now show you the pupa of a gnat. It is one 

 of the most useful of all my best objects, for which I 

 have the greatest regard. Before I ask you to see in it, 

 amongst examples of a higher nature, an illustration of the 

 truth I have already reminded you of, that the more we 

 magnify the more we see, let me repeat one or two facts in 

 the gnat's life with which, probably, you are not acquainted. 



I wonder how many people know that the gnat in the 

 first two parts of its life is aquatic that it lives in the 

 water ? Mrs. Gnat is a boat-builder, and she knows that, 

 although in her perfect form that in which you are 

 best acquainted with her water would-be death to her, 

 any other element but water would be death to her off- 

 spring. So, seeking some bit of weed or any floating par- 



Egg-boat of the common gnat. 



ticle which she may find on the pond or running stream, 

 you may, during the summer-time, see her and her busy 

 companions actively occupied in skimming over the water. 

 They are seeking some substance, whatever it may be, upon 

 which they may securely deposit their eggs. Having 

 decided what it shall be, one after another is laid upon 

 it, until about two hundred and forty may be counted. 



Now, in what form do you think this beautiful 

 creature has been instructed to build up its kind of 

 floating nest for her interesting family, who are to live, 

 remember, not as she does in the air, but in the water ? 

 Well, it is a boat; exactly in the form of a Thames 

 " wherry " a boat without oars, but which can never be 



