IN THE FIELD 201 



but the young caterpillar's appetite is so great that it must 

 spend most of its time in eating. As caterpillars dwell 

 literally on their bread, and eat so voraciously, they must 

 grow very fast. Within a few weeks they are full grown, 

 and each one then weighs probably about one hundred 

 times as much as it did when it left the egg. Would the 

 biggest cow weigh as much as one hundred calves ? You 

 can find out by observation within about how many days a 

 caterpillar eats an amount of food which weighs as much as 

 itself. If a man ate as much in proportion to his weight 

 as a caterpillar, how many oxen could he eat up in a year ? 



The chrysalis. You know, from observation, that what 

 we have said about the caterpillar's appetite is entirely 

 true ; nevertheless, there comes a time when these voracious 

 eaters seem to get sick. They stop eating, and move about 

 restlessly. This is a sign that they are about to change 

 into the pupa, or chrysalid state. They prefer a place 

 where they are sheltered from rain and snow, and for this 

 reason the chrysalides are frequently found under the top 

 boards of fences, where they pass the winter. From these 

 chrysalides the butterflies emerge on the first warm days of 

 spring. In early summer they frequently pass through the 

 chrysalis stage on their food plant. The caterpillars of 

 this butterfly, as those of all others, moult several times 

 before they attain full growth. When a caterpillar is ready 

 to moult, the skin breaks open on the back, and the cater- 

 pillar works itself out of it. Many caterpillars eat their 

 cast-off skin. The processes of moulting, of changing into 

 a pupa, the emerging of the butterflies from the chrysalides, 

 should be observed by the children on specimens raised by 

 themselves, and they may then describe the process in full. 



Remedies. The best friends of the farmer and gardener 

 are insect-eating bi/ds and mammals, and those we should 

 protect. 



