2G STBUCTUBE OF THE LEP1DOPTEEA 



structure. The first point that strikes our notice is the division of 

 its body into segments or rings, separated from each other by a 

 more or less distinct line or slight constriction of the body. 



There are thirteen of these segments, reckoning, as is usual, the 

 head as the first. 



The head is usually very hard, and often of a much darker 

 colour than the rest of the body. It is also frequently divided into 

 two lobes by a couple of oblique lines, between which the parts of 

 the mouth are situated. The two powerful horizontal jaws, to 

 which we have already referred, are very hard and sharp, and 

 curved like a sickle, and therefore splendidly adapted for biting from 

 the edges of leaves. The head is also provided with a pair of 

 antennae, usually very short and inconspicuous and protected by a 

 horny covering. 



Unlike the perfect insect, the caterpillar has no large compound 

 eyes, but twelve very small simple eyes, situated on the cheeks, 



very near the mouthsix on each 

 side. 



If you examine them with a mag- 

 nifier, yoM^ Bee that each one is pro- 



FIG. 19.-THE CATERPILLAR OF vided with a sma11 and verv convex 



THE ANGLE SHADES MOTH lens a lens of very short focus, such 



'Meticulosa). as w r ould be used for the examination 



of small objects held very near to 



the eye. From this arrangement we should be inclined to con- 

 clude that the caterpillar caji see only those objects that are 

 close to its mouth ; and this idea is strengthened if you place 

 one in a box containing a number of leaves, one of which is 

 that of its own food plant. It will wander about the box, appa- 

 rently looking at every part of every leaf it passes, after the 

 manner of a very short-sighted individual, and never taking a 

 general look round. A butterfly or a moth can see a flower in 

 the distance, for it flies unhesitatingly from one to another in 

 the straightest and shortest path, but if you place a caterpillar 

 in the centre of a ring composed of a leaf of its food plant and 

 nine others from other plants, the chances are (nine to one) that it 

 will not walk towards what it would like to have. 



Again, the eyes are situated on the lower part of the cheek, 

 directed slightly downward, and are therefore adapted for seeing 

 what is just under its jaws as it walks along. Had we no knowledge 

 whatever of the caterpillar's twelve little eyes, we should probably 



