77 



takes its course over the tree or bush for food : thu* 

 many hundreds of them form a regular republic. The 

 separate cell of each is finally the place where it passes 

 its change into theaurelia and perfect state ; but many 

 species do not separate even then, but are found in 

 their aurelia state, all huddled together, numbers of 

 their cases making one confused mass. 



One thing more is highly observable in them, the 

 regularity of their marches : they are exactly obedient 

 to their chief. When they change their quarters, one 

 inarches single first, two others follow, and keep their 

 bodies very nicely in the same position with his. After 

 these, there follows a large party : these regulate their 

 motions by the former, and so the order is csntinued 

 through the whole company. When the leader turns 

 to the right or left, the whole body does the same in- 

 stantly. When he stops, they all immediately stop ? 

 and march again the moment he advances. 



20. The outward covering of the body is in many 

 animals changed several times, but in few more fre- 

 quently than the caterpillar. Most of these throw it 

 off at least once in ten days. Indeed in the whole in. 

 sect-class, the most numerous of all animated beings, 

 there- is scarce one which does not cast its skin, at lear.t 

 once before it arrives at its full growth ; but the ca. 

 terpilta.r changes more than his skin; even the outward 

 covering of every, the minutest part of its body. And 

 what they throw off has the appearance of a complete 

 insect, presenting us with all the external parts of a 

 living animal. If the caterpillar be of the hairy kind, 

 the skin it throws oiF is hairy, containing the covering 

 of every hair. And even the claws and other parts 

 that are not visible without a microscope, are as plain 

 in this as in (he living animal. But what is more 

 amazing is, that the solid parts of the head, the skull 

 and teeth are distinguishable therein. The throwing off 

 an old skull and teeth, to make way for new ones, is 

 an act beyond all comprehension. A day or two be- 

 fore, the creature refuses to eat, and walks very slowly 

 E 3 



