174 



THE YOUNG NATURALIST. 



very wonderful. Everyone must have noticed 

 them flying about a horses' head when driving 

 out on a hot day. They will play about with 

 as much ease as if the horse was motionless, 

 yet they keep up with it all the time, and even 

 as it tosses its head, they rise and fall with the 

 motion. If the horse be running at ten miles 

 an hour, they must fly at treble the pace, and 

 this too, not in pursuit of prey, or to escape 

 an enemy, but merely in their summer day's 

 gambols. Some liies have a singular habit of 

 poising themselves in the air, and remaining 

 quite motionless, ezcept the vibration of their 

 wings, hovering as the Kestril does, attempt 

 to catch one, and it is off with the quickness of 

 light. One of my boys called my attention to 

 a peculiarity of one of these "poisers." I 

 asked him if he could catch one as it hovered 

 motionlesss in the greenhouse. "No," he 

 said, " but I can make it alight on my finger." 

 He cautiously approached it with his upraised 

 finger ; and when it was within three or four 

 inches off the fly, it dropped on to the end, 

 and sat there. This he repeated several 

 times : the fly always sitting on the end of the 

 upraised finger, and remaining there until 

 disturbed. Fig. 7, PI. 1, is one of these 

 " poisers," and is called Pendulus similis. 



As an order the Diptera are much neglected 

 by Entomologists generally ; and doubtless 

 many new species will be discovered when 

 there are more workers in it. 



We have now completed this series of 

 papers. Authors recognise a few additional 

 orders, but we have named the principal. 

 The order Aptera includes wingless species, 

 such as fleas and lice ; and others have been 

 formed for the reception of insects that do 

 not fall very readily into any of the larger 

 orders. 



Our readers will now be able to form a 

 pretty correct idea as to the order to which 

 any insect belongs that they find ; and in a 

 very early number we will commence with a 

 series of papers with fuller details of the 

 species. These will begin with British Butter- 

 flies, and will be illustrated with figures of 



every species, of varieties, and of the larvse 

 and pupae, of all we can obtain for figuring. 

 We are anxious to figure in all cases from 

 nature, and beg our readers' kind assistance. 



VEGETABLE NUTRITION 



AND 



INSECTIVOROUS PLANTS. 



Abstract of a lecture delivered at Hudders- 

 field, on March 9th, by Professor Williamson, 

 President of the Yorkshire Naturalists' Union, 

 being the fifth of a course of Gilchrist Science 

 Lectures. 



Plants are composed chiefly of carbon, and 

 this is proved by a very simple experiment, if 

 we take a piece of wood and burn it, without 

 letting the air get to it, it will be converted 

 into pure carbon— charcoal ; but if we burn it 

 in the open air a very different result follows, 

 all that remains after the burning is a few 

 ashes, all the rest has passed away in invisible 

 gases — carbonic acid, oxygen, hydrogen, and 

 nitrogen. In the ashes which remain we find 

 in very small quantities — lime, potash, soda, 

 a very small proportion of iron, and in such 

 plants as grasses and canes — silica or flint. 

 By what manner, and by what machinery 

 do these plants get at these materials ? If 

 you take any plant, and cut a thin slice from 

 the stem, and place it under a microscope, 

 you will find that it is made up of a number 

 of little bags or cells filled with a jelly sub- 

 stance. No matter how small or how large 

 the plant may be it will still be made up of 

 these minute cells. Then among these cells 

 we have long tubes or vessels, through which 

 the circulation of the plant passes. If we 

 make a thin slice of some green leaf we shall 

 find that it too is made up of little cells, but 

 inside these cells will be little green specks, 

 called chlorophyl grains, which gives the 

 color to the leaf, Wherever a plant is green 

 these grains are there. Leibeg, the German 

 chemist, thought that plants derived all these 

 substances which we find in their tissues 

 through their roots, but this has been found 



