174 



MOTION OF CATERPILLARS. 



muscles. There are usually five pairs of these four of them 

 succeeding the true legs, and another proceeding from the last 

 segment of the body. Those possessing pro-legs on nearly every 

 segment, crawl upon all the feet at once, after the manner of 

 the Myriapoda; but those which have only a small number of 

 pro-legs adopt a different method. They seize fast hold of the 

 objects on which they are stationed, with the six true legs at 

 the fore part of the body, and then elevate the intermediate 



segments into an 

 arch, until they 

 bring the pro-legs 

 behind close to the 

 others ; they then 

 disengage the true 

 feet, and retaining 

 hold with the pro- 

 legs, they thrust the 

 body to its full 

 length, and then re- 



PIO. 497.-CATKRPILLAR AND CHRYSALIS OF MAGPIK MOTH. COmmCnCC the Same 



manoeuvre, which 

 they execute very quickly. They are called, from this circum- 



Fio. 498. 1. CATERPILLAR OF SWALLOW-TAILED MOTH (Ourapteryx Sambucaria). 

 2. CATERPILLAR OF PRIVET HAWK-MOTH (Sphinx liyustri). 



stance, Loopers or Geometers. Many of them resemble small 



