INTRODUCTION 17 



usually in the direction of the loss of green colouring, but 

 perhaps also sometimes influenced by other physical causes, or 

 by a leaning towards a protective dress. The earlier stages 

 are often also more or less different, but are not described, 

 as they would have required a very considerable amount of 

 additional space ; they are moreover less distinctive, less 

 known, and less likely to be met with. 



The food-plants are in general recorded under their scientific 

 names only, except in the case of a few of the most familiar and 

 unmistakable trees and shrubs (oak, elm, hawthorn, hazel, 

 etc.) ; every entomologist ought to have some acquaintance 

 with practical botany, but for the convenience of beginners an 

 appendix is added giving the ordinary English names of those 

 plants which are generally well known. If more than one food- 

 plant is recorded, they are placed, so far as possible, in the 

 usual order of preference, that which is most commonly pre- 

 ferred by the larva being placed first. Some larvae (especially 

 amongst the Garadrinina) are remarkably indiscriminate in their 

 choice ; in such cases a full list of recorded food-plants would 

 be long and useless ; three or four only are given as examples of 

 those generally chosen, followed by an etc., which may usually 

 be taken to include many plants more or less nearly allied to 

 those mentioned. 



GLOSSARY 



anastomose: to unite for a certain caudate: with a tail -like projec- 



distanoe and sonarate ngain. tion. 



antcmedian : before the middle. cliitine : a horny substance, forming 



anterior : nearer to the head. the hard structures of insects. 



apodal: without legs. cilia: fine hairs. 



apterous: without wings. ciliated: with series of cilia. 



areola: a secondary cell formed by dilations: antennal series of cilia. 



anastomosis of veins. concolorou.i : of the samo colour. 



bicolorous : of two colours. connate : rising from the same 



tiouspidate: forming two points. point. 



bifid: centrally cleft. correlated: derived from the same 



bipecihiated : with two series of ancestral form. 



pectinations. costa: upper margin of wing. 



