188 APPLE-TREE CATERPILLAR ITS TIMES OF FEEDING. 



or gnaw a slight notcli in its side, for a meal, and as soon as 

 they have fed thus much it can be seen that their bodies are 

 more plump, and fine whitish lines begin to appear upon them. 

 As they increase in size, and especially each time they change 

 their skins, their color becomes more diversified. They change 

 their skins five or perhaps six times at intervals of from three to 

 nine days, the worm gaining from an eighth to a quarter of an 

 inch in length each time it throws off* its old skin. 



When young they go out to feed much less frequently 

 than when they are larger. They move about entirely at hazard 

 in search of food, having no power of smell or other sense to 

 guide them, as I infer from having placed apple and cherry 

 leaves in the direction in which famishing worms were travel- 

 ing, and seeing them pass quite near and almost touching such 

 leaves without discovering them. Nor when a store of food has 

 been discovered by some of the worms of a starved nest, have 

 they any mode of communicating the information to the others. 

 The rest of the nest probably discover the fact that some of their 

 comrades have obtained a full meal, and thus know that food is 

 somewhere within their reach, but they are obliged to wander 

 about at hap-hazard until they find it. And I have noticed one 

 hungry worm and another after examining the end of every twig 

 upon a limb unsuccessfully for food, on returning down the limb 

 meet several others going out upon the same errand; yet they 

 pass their comrades without those who are coming in having 

 any mode of informing those who are going out that their jour- 

 ney will be wholly fruitless. 



As a general rule each nest has its stated hours for feeding and 

 for repose, all the worms going out and returning in a regular 

 procession, one after another. They repair to a particular limb 

 of the tree, frequently a limb which is distant from the nest, 

 and there feed together, occupying every leaf and three or four 

 worms often eating upon one leaf. In pleasant weather they 

 have usually three meals in twenty-four hours, one in the morn- 

 ing, one in the afternoon, and another in the night. But there 

 is much irregularity in all these points of their history. A part 

 of the worms are often at rest in their nest while the others 

 are out feeding. And when they are about to cast their skins 



