174 HABITS AND INSTINCTS OP ANIMALS. CHAP. V. 



which transfixed it, and devour the other insects con- 

 tained in the entomologist's box.* This vitality, and 

 insensibility to pain, is manifestly a wise and merciful 

 provision of the Almighty towards those of his creatures, 

 which, of all tohers, are most liable to accidents, from 

 the number and variety of their enemies. 



(190.) The preceding remarks are chiefly confined 

 to what are usually, but inaccurately, termed true in- 

 sects ; but, as the crabs, spiders, intestinal worms, and 

 red-bloode&Annelides, or sea worms, are truly annulose 

 animals, they come within the limits of this section. 

 These, however, will not long detain us. The crabs 

 are the most completely armed of all apterous insects, 

 their formidable fore claws acting both as offensive and 

 defensive weapons ; while the resolute courage with 

 which these creatures will threaten to repel an injury, 

 very often secures them from a real one. Like the 

 crane flies (Tipula) we have just mentioned, most of 

 the crabs, in order to free themselves from restraint, 

 will cast off a limb, and scramble away as if nothing 

 had happened. The same occurs with spiders ; and the 

 vitality of the intestinal worms is well known. Of the 

 means of defence possessed by sea worms (Annelides\ 

 we are altogether ignorant ; while those enjoyed by the 

 barnacles (Cirripedes) seem to be entirely passive: they 

 retire, on the first appearance of danger, within their 

 shelly coverings, close the valves or doors of their ha- 

 bitations, and effectually exclude all intruders. 



(191.) The defences possessed by the Mollusca, or 

 soft-bodied animals, composing the polypes (Acritd), 

 the shellfish (Mollusca), and the sea stars, or radiated 

 class (Radiata), possess little of that popular interest 

 (so far as our limited acquaintance with their history 

 enables us to judge) which belongs to the more perfect 

 animals. Generally speaking, they secure their safety 

 by passive resistance. The testaceous animal instantly 

 withdraws itself into its shell, and is secure. The slug, 

 being naked, contracts itself into a heap, and throws 



* Kirby, vol. ii. p. 229, 



