Instructions for collecting Insects. 2 1 9 



should be of gauze. As many species of caterpillars enter the 

 ground to be there transformed into the chrysalis state, it is necessa- 

 ry that there should be, at the bottom of the box, a bed of light 

 earth two or three inches in thickness. That the caterpillars may 

 not perish for want of nourishment, they must be furnished with fresh 

 plants. It will not be necessary to change the plants often, if one 

 has the precaution to put the stalks into a vessel full of water, accor- 

 ding to the practice of preserving, for several days, flowers in a room. 

 The vessel should be placed in the middle of the box, and closed 

 by a cover perforated with holes. These holes being stopped by the 

 stalks, the caterpillars cannot drown themselves, as would often hap- 

 pen, should the vessel be uncovered. The caterpillars, after arri- 

 ving at their full growth, will form their chrysalis, and, in a longer or 

 shorter time, the butterflies will appear. 



It is necessary to avoid handling the chrysalides, as it will tend to 

 destroy them. 



One may put into the box the chrysalides taken in his rambles, 

 either by means of the trowel or in any other way. A chrysalis^ that 

 is injured, should be thrown away, as it will never revive. 



The lepidopters, whose caterpillars are suspended before their 

 transformation, commonly hatch at the end of fifteen days at the 

 least, or thirty days at the most. 



The caterpillars, that inclose themselves in a cocoon, remain a 

 longer time in the chrysalis. Generally the consistence of the co- 

 coon is proportioned to the continuance of the time, which is very 

 variable. There are some lepidopters, that hatch at the end of a 

 month ; others in two or three months ; and some, that continue a 

 year or more in the chrysalis. The species, that go into the earth, 

 remain there from a month to a year. 



.1 will not close this article without warning the collector against the 

 prejudices of infancy, which might inspire him with disgust and 

 even horror at the caterpillars. They are no more dangerous than 

 the butterflies, that proceed from them. Nevertheless, should he 

 meet in the woods, and particularly at the root of oaks, with those 

 large nests of caterpillars full of dried skins, he must approach them 

 with caution. The hairs, which the wind might blow on his skin, 

 would occasion painful itchings. 



The dipters, (of which the flies form a part,) are not in the least 

 dangerous. They may all be seized with the hands ; but, as they 

 are very active, it is scarcely possible to take them without recourse 

 to the net or the rackets. 



