AND THE LOWER ANIMALS. 53 



comparison, let us see in what this phenomenon con- 

 sists, as we find it among insects where it has been 

 longest known and most fully investigated. We shall 

 select the Lepidoptera, commonly called butterflies, as 

 an example, and study the life-history of one of the 

 commonest species — the cabbage-butterfly (Pieris 

 Brassicce), which we can do almost with certainty 

 by bringing together the facts observed by different 

 naturalists. 



All our readers must have seen these butterflies in 

 their gardens, or in the country; they have black 

 bodies, white ringed antennae, and wings which are 

 white on the upper side, but yellowish below, and 

 covered with black spots, whose number and position 

 mark the sexes. They are frequently seen in the 

 months of August and September flying in pairs, 

 sometimes in pursuit of each other, and occasionally 

 rushing round and round, as though engaged in some 

 severe contest. It seems as if a real struggle was 

 going on. It is absolutely nothing of the sort ; it is 

 the prelude of sexual union, and has been investigated, 

 described, and figured in all its stages by Reaumur, 

 whose talent for observation seems almost to have 

 amounted to genius.* The male urges his suit, and 

 the female rejects it in true coquettish spirit. Finally, 

 she settles down, but her wings are closely applied to 

 each other, in this way covering the entire body. The 

 male moves round and round her for a few moments, 

 and then, as if he had taken his final departure, flies 



* " Memoires pour servir a l'Histoire des Insectes," torn. i. 1734. 

 This work, in six large volumes 4to, is accompanied by a great 

 number of plates, and even at the present day is unequalled of its 

 kind. 



