CHAPTER III. 



GEOMETRY. 



The large and important group of Geometr.e, or Loopers, now 

 come before us. These appropriate terms are applied to the 

 Moths on account of the mode of progression adopted by the 

 larva. The caterpillars are so constructed that they cannot 

 ■walk after the usual fashion of such beings. The reader will 

 remember that the caterpillars hitherto mentioned have a 

 number of false legs, or claspers arranged on the under side of 

 the body, in addition to the six true legs which are situated 

 on that part of the body which will afterwards become the 

 thorax of the perfect insect. Most caterpillars have five pairs 

 of these claspers, but the Geometra larvse have only two pairs, 

 which are set closely together at the very end of the body. 

 The caterpillar is therefore o'bliged to adopt a peculiar mode 

 of progression. 



When it wishes to move, it clings very firmly with its true 

 legs, loosens the grasp of its claspers, and draws them close to 

 the legs, so that its body is brought into an arch or loop. 

 The claspers then fix themselves tightly to the object on which 

 the caterpillar is moving, and the body is stretched out in 

 order to find a fresh foothold for the legs. Thus, the cater- 

 pillar proceeds by bringing its body into the loop-like form 

 and stretching it out for another hold. This may seem an 

 awkward mode of progression, but it is nothing of the kind. 

 There is even a ' soii; of grace about the movement, and the 

 caterpillar gets along at a wonderful pace, forming its succes- 

 sive loops with a rapidity that seems almost incredible. 



The muscular strength of these caterpillars is wonderful. 

 Most of us have seen acrobats fix their feet to an upright pole, 

 or grasp it with their hands, and stretch out their bodies 

 horizontally. This attitude requires great muscular powers 



