INTRODUCTION. 83 



genera of some extent, and distributed over several 

 countries, are in the same condition. 



" What we have just stated, applies equally to 

 the correlation of species with each other. If we 

 take, for example, the genus Satyrus of Latreille, 

 we perceive that it is composed of an infinite num- 

 ber of secondary groups, scarcely any of which are 

 proper to one country. Thus, in Europe, we have 

 the division to which Galatea belongs, extending 

 along the basin of the Mediterranean, even into 

 Persia; that of Hermione, which takes the same 

 direction, and continues to Cachmere; that ofNorna> 

 proper to the polar regions of the two continents ; 

 that of Nigres, which inhabits mountainous coun- 

 tries, and is found only at the Cape and at Chili ; 

 finally, that of the Satyres, properly so called, which 

 are connected with the species of New Holland, 

 some of them with those of Chili, of North Ame- 

 rica, and Siberia. America and the East Indies, 

 likewise, present groups which in general appear- 

 ance differ widely from our 'European species; 

 while there are others which resemble several at 

 the same time. A collection of the Satyres of one 

 country would, therefore, form a sufficiently natural 

 series; but it would appear most irregular when 

 the species of several countries were brought to- 

 gether. 



" Our method is partly founded on the caterpillar, 

 and partly on the perfect insect. We attach the 

 greatest importance to the caterpillar state, and the 

 characters which.it furnishes have often more value 



