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 of Noma , 
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 
