236 THE BOOK OF THE OPEN AIR 



the eggshell. To enable it to make course, the whole period occupied in 

 its debut the young caterpillar bites passing from egg to butterfly not much 

 through the shoulder of the egg, and exceeding six weeks in the summer- 

 before it emerges therefrom it has time. 



eaten a large portion of the shell. It Some butterflies require the whole 

 is of course exceedingly small at first, of twelve months to effect the changes 

 and very unlike what it will become from egg to perfect insect, whilst of 

 when full-grown. Its existence as a others there will be three generations 

 caterpillar is of comparative short during the year. Hibernating species 

 duration; but this stage is nevertheless such as the brimstone and tortoise- 

 a most important one in a butterfly's shells are in the butterfly state for at 

 career, and full of stirring episodes, least six months, but they are in a 

 Not only has it to pass through the dormant condition during the greater 

 ordeal of changing its skin on several part of that time. Even so their 

 occasions, but enemies, especially those active life is longer than that of the 

 in the shape of parasitical flies, are small copper, of which there are three 

 ever on the watch to destroy it. The flights of butterflies in the year. The 

 flies deposit their eggs on the back of duration of the caterpillar life is also 

 the caterpillar, and the tiny grubs a variable quantity. In some kinds 

 that hatch from these enter its body this stage is protracted over several 

 and therein establish themselves as months, whilst in others it lasts only 

 non-paying guests. Caterpillars so com- a few weeks. Then as regards the 

 mandeered often succeed in attaining chrysalis, some kinds remain much 

 the chrysalis stage, but this probably longer in this stage than others, 

 only happens when the parasites are Down yonder lane, on the sunny 

 later than their host in arriving at side of the old barn, there is a fine patch 

 maturity. Although a large, some- of nettles, and on these we shall most 

 times very large, percentage of cater- likely find a colony of spiny cater- 

 pillars are " ichneumoned," some cer- pillars busily engaged in devouring 

 tainly do escape the attention of these the leafage, or perhaps they may be 

 undesirables and other foes, and sunning themselves on the web of silk 

 therefore reach the chrysalis stage in which is the result of their co-operative 

 a healthy condition. From such industry. This web may be regarded 

 chrysalides butterflies emerge in due as the common hall of the colony, in 



