156 LIFE, IN ITS INTERMEDIATE FORMS. 



The power of these organs, so delicate and filmy in 

 appearance, we have before alluded to, but it may be illus- 

 trated by another anecdote. Leeuwenhoek has recorded 

 a remarkable instance, in which he was an eyewitness of 

 the comparative capabilities of the Dragon-fly and the 

 Swallow, as relates to the perfection of their flight. The 

 bird and the insect were both confined in a menagerie 

 about a hundred feet long ; and apparently their powers 

 were fairly tested. The swallow was in full pursuit, but 

 the insect flew with such astonishing velocity, that this 

 bird of rapid flight and ready evolution was unable to 

 overtake and entrap it ; the insect eluding every attempt, 

 and being generally six feet before it. 



The organs of the mouth vary much in form and func- 

 tion in different insects. In a Beetle they consist of two 

 pairs of jaws, generally hooked and toothed, working hori- 

 zontally, and an upper and an under lip, closing the mouth 

 above and below. Each lower jaw bears one or two fila- 

 ments, consisting of several joints ; and a similar pair is 

 affixed to the lower lip. These filaments are called palpi, 

 and are supposed to be highly endowed organs of touch. 

 They greatly resemble the antenna, or horns of many 

 joints, which project from the front of the head; but 

 these latter are considered to be organs of hearing. 



If we look at a Gnat piercing our hand with its blood- 

 sucking tube, or a Butterfly pumping up the nectar of a 

 flower through its spiral tongue, or a Fly dissolving grains 

 of sugar with the fleshy lips of its proboscis, we shall not 

 very readily allow them any analogy with the apparatus 

 of jaws and lips which we have just described. Yet great 

 as is the dissimilarity, it is now established, that all these 



