INTRODUCTION. XIX 



Hymenopterous parasites, chiefly belonging to the group Proc- 

 totrypidcc, which deposit their eggs on or in those of other 

 insects, the contents of which serve as food for their own larvae. 

 Some of these parasites, especially those belonging to the family 

 Mymaridce, or Fairy Flies, are among the smallest insects 

 known, and are extremely elegant microscopic objects, with 

 battledore-shaped wings, set round with a fringe of long hairs. 

 They are sometimes just visible as specks on a window-pane. 



It is even possible to classify Butterflies by the structure of 

 their eggs, without reference to other characters. This has 

 been attempted by Mr. W. Doherty in respect to Indian 

 Butterflies ; and he published his preliminary results in the 

 "Journal of the Asiatic Society of Bengal," vol. 55, pt. 2, 

 pp. 107-111 (18S7). From this paper most of the characters 

 given for the eggs of the families of Butterflies in the present 

 work have been taken. We will presently make some ex- 

 tracts from his tentative notes on the classification of Butter- 

 flies according to the eggs. It must be noted that he employs 

 Apatura not for A. iris but for A. bolina, for which most 

 authors use the generic name of Hypolimnas or Diadema ; 

 also that for practical purposes he himself employs a classifi- 

 cation in which other characters besides the eggs are taken 

 note of. This enlarged system we shall not further notice here. 



" I am not sure that the eggs form a good guide to a 

 primary division of Butterflies. Even if I were sure," Mr. 

 Doherty writes, " I should hardly have the courage to alter 



the received classification to the required extent 



Judged purely by the egg, the classincation of Butterflies would 

 be something like this : 



" 1. Danaiform Group, including the Danaidtz, Acrccida, 

 and Ifc/icvniidte, connected with the Apaturidce by Cynthia 

 and Ccthosia. (Egg radiate, much higher than wide, 

 leathery.) 



B 2 



