232 SCIENTIFIC ILLUSTRATIONS [Mor 



stantly cultivated by their minister, but who relapse into their 

 former littleness if his care is withdrawn. Such men, like the 

 pansies, give a deal of trouble. Eut if you want to exhibit 

 either them or the flower, you have no option but to give them 

 constant cultivation. Whether the result, in either case, is 

 worth the trouble is another matter. B. F. 



Moral Sentinels. 



The Trigonocephalus or lance-headed viper is a most poison- 

 ous reptile, common in the West Indian Islands. To warn the 

 natives in the Antilles of his presence, Nature has supplied us 

 with numerous watchful sentinels in the small birds, whose 

 not unreasonable hate against this serpent is a remarkable 

 proof of their intelligence. No sooner does the bird, which 

 they have wished to name the nightingale, see from his aerial 

 station the scales of the reptile gliding into the herbage, or 

 glittering among the large leaves, than he can no longer control 

 himself. He flies to and fro : he leaps from branch to branch, 

 summoning with a lamentable cry all the feathered tribe from 

 the neighbouring trees. From far and near the cry widens and 

 is repeated ; from all directions flock nightingales and thrushes, 

 grosbeaks and humming-birds, and hovering above the assassin 

 furiously denounce it, and indicate its lurking-place to man. 

 Irritated by such a concert of maledictions, the serpent elevates 

 its crest, but lo ! they are far beyond its reach ! And the cries, 

 the murmurs, the insults are redoubled. It seeks to conceal 

 itself, but these cries persistently accompany it. Wherever it 

 drags its slimy, shining bulk, they follow, they harass, and 

 they denounce it. Either night comes on, or it succeeds in 

 completely hiding itself from their watchful gaze, before they 

 reluctantly leave it to its own devices. Great the consternation 

 if their enemy escape them. But what joy, what triumphal 

 sounds, if man appears upon the scene, and slays it ! These 

 birds resemble those moral sentinels in society, the preachers, the 

 teachers, and the philanthropists, w^o endeavour by their acti- 

 vities and their voices to warn mankind against the insidious 

 movements of " that old serpent the devil." How energeti- 

 cally do these good men perform their noble work ; how wary 



