274 APPENDIX /. 



gravid with eggs, and inclose her beneath a gauze cov- 

 ering upon the growing plant. If it be a tree or bush, 

 tie a muslin bag over a bough, taking care that there 

 are some tender leaves upon it (and no ants), and so 

 arrange the bag that the butterfly may rest naturally 

 upon them ; inclose the butterfly and she will pretty 

 certainly deposit eggs in the course of a day or two. Or, 

 if the plant be one of small size, use a headless keg, 

 covered at one end with gauze ; even a discarded vege- 

 table can will servo the purpose. 



After a day's or two days' confinement, the prisoner 

 should be set free. If she has not then laid eggs, she 

 probably cannot, and she should be released. If she 

 has yielded the desired harvest, she should be rewarded 

 with liberty. When obtained, the leaves or twigs upon 

 which the eggs are found may either be left where they 

 are or carried home to more convenient quarters. 



It is not easy to preserve eggs entire. If they do not 

 hatch they are apt to shrivel, excepting such as have a 

 dense pellicle, like the hemispherical eggs of the smaller 

 skippers or the echinoid eggs of the blues and cop- 

 pers ; it is nearly impossible, too, to prick the egg and 

 save its form. The best way is to watch for the egress 

 of the caterpillar and the moment it is free separate it 

 from the shell, which it will otherwise devour ; in that 

 way I have obtained a considerable collection of these 

 little gems. Or they may be obtained from the plants 

 on which they have been laid naturally, by searching the 

 food plants carefully ; they are not so difficult to detect 

 as might be supposed ; many of these will be found at- 

 tacked by minute parasites, which generally make their 

 exit through a single minute hole, leaving the egg in 

 an admirable condition for the cabinet. The eggs can 

 then be gummed, with or without the leaf on which 

 they are laid, upon triangular bits of card-board, 

 pinned and transferred to the cabinet. Inspissated 

 ox-gall, diluted with an equal quantity of thick gum 

 arabic, makes the best material for attachment to the 

 card. 



