IX. OUTSIDE AND IN. 



77 



tube, each leaf articulates itself with the rest of 

 the stem at a ringed knot, or joint. 



Before examining these, remember there 

 are mainly two sorts of joints in the frame- 

 work of the bodies of animals. One is that 

 in which the bone is thick at the joints and 

 thin between them, (see the bone of the 

 next chicken leg you eat,) the other is that 

 of animals that have shells or horny coats, 

 in which characteristically the shell is thin 

 at the joints, and thick between them (look 

 at the next lobster's claw you can see, with- 

 out eating). You know, also, that though 

 the crustaceous are titled only from their 

 crusts, the name ' insect ' is given to the 

 whole insect tribe, because they are farther 

 jointed almost into sections ; it is easily 

 remembered, also, that the projecting joint 

 means strength and elasticity in the creature, 

 and that all its limbs are useful to it, and 

 cannot conveniently be parted with ; and FlG - 22 - 

 that the incised, sectional, or insectile joint means 

 more or less weakness,* and necklace-like laxity or 

 license in the creature's make ; and an ignoble power 



* Not always in muscular power ; but the framework on which 

 strong muscles are to act, as that of an insect's wing, or its jaw, is 

 never insectile. 



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