6o 



ARTICULATED ANIMALS. 



greatest strength and firm- 

 ness are necessary ; and 

 scarcely any traces are left 

 to indicate their existence as 

 separate pieces ; so that, in- 

 stead of exhibiting that suc- 

 cession of similar segments 

 seen in the centipedes, the 

 body becomes divided into 

 three distinct portions; name- 

 ly, the head, which contains 

 the organs of the senses and 

 the parts of the mouth, the 

 thorax, supporting the limbs, . 

 or instruments of progres- 

 sion, and the abdomen, en- 

 closing the viscera subservi- 

 ent to nutrition and reproduction. (Fig. 54.) 



FIG. 54. DIVISIONS OF A BEETLE. 



FIG. 55. SCORPION AND CENTIPEDE. 



In the fourth division of articulated animals, namely, the 

 Arachnida (scorpions, spiders, &c.), a still further consolidation 



