INTRODUCTION. xxxv 



are brought into the harbor at Falmouth alive and impounded in a box for sale, and 

 the shells are branded with marks by which every man knows his own fish. The 

 place where the box is sunk, is four miles fi-om the entrance to the harbor, and that is 

 above seven miles from the place where they are caught. One of these boxes was 

 broken ; the branded crabs escaped, and two or three days afterwards they were 

 again caught by the fisherman at the Lizard rocks. They had been carried to Fal- 

 mouth in a boat. To regain their home they had first to find their way to the mouth 

 of the harbor, and when there, how did they know whether to steer to the right or to 

 the left, and to travel seven miles to their native rocks?" It is scarcely possible to 

 regard such an instance of what has been called the ' homing instinct,' as a purely 

 physiological, reflex act, nor to consider the crab a mere automaton. 



Mr. Darwin, in his Descent of Man, refers to the curious instinctive habits of the 

 large shore-crab {Birgus latrd), which feeds on fallen cocoa-nuts, " by tearing off the 

 husks fibre by fibre ; and it always begins at that end where the three eye-like depres- 

 sions are situated. It then breaks through one of these eyes by hammering with its 

 heavy front pincers, and, turning round, extracts the albuminous core with its narrow 

 posterior pincers." 



Little is really known of the instincts and other intellectual traits of the crusta- 

 ceans — but when we come to the insects the literature is very extensive, thanks to the 

 observations of Reaumur, Bonnet, De Geer, Wyman, Bates, Belt, MtlUer, Moggridge, 

 Lincecum, McCook, Sir John Lubbock, and others. 



As we have stated in our Half Hours with Insects : " Those who observe the ways 

 of insects have noticed their extreme sensitiveness to external impressions ; that their 

 motions are ordinarily rapid and nervous. Look at the ichneumon fly as it alights on 

 a leaf near a caterpillar : with what rapid motions it walks and flies about ; how swiftly 

 its feelers vibrate ; how briskly it walks up and down surveying its victim. Look at a 

 ■ mud wasp as it alights near a pool of water to moisten its mouth. How nervous are 

 its motions, how nimbly it flies and runs about the edge of the water. The ant is a 

 busy, active, dapper little creature, a nervous brusqueness pervading its movements. 

 How susceptible insects are to the light may be tested on a damp, dark night by open- 

 ing the windows. In dart a legion of insects of all sorts, each with a diiferent mode 

 of entrance, some beetle boldly flying about the room in its blundering noisy flight, or 

 a Clisiocampa moth enters with a bound, and a series of somersaults over the table, 

 like the entree of a popular clown into the ring of a circus, though the latter may have 

 tlie most self-possession of the two. 



" Insects are, like most animals, extremely sensitive to electrical phenomena. Just 

 before a thunder shower they are particularly restless, flying about in great numbers 

 and without any apparent object. The appendages of insects, their feelers and their 

 legs, must be provided with exquisitely sensitive organs to enable them to receive im- 

 pressions from without. Everybody knows that insects have acute powers of sight. 

 That they also hear acutely is a matter of frequent observation. Often in walking 

 through dry bushes, the noise of one's feet, in crushing through the undergrowth, starts 

 up hosts of moths, disturbed in their noonday repose. If insects did not hear acutely, 

 why should the Cicada have such a shrill cry ? For whose ears is the song of the cricket 

 designed unless for those of some other cricket ? All the songs, the cries, and hum of in- 

 sect life have their purpose in nature and are useless unless they warn off or attract 

 some other insect. 



" We know with a good degree of certainty that some insects have an acute sense 



