362 RECREATIONS OF A NATURALIST 



larva, and whether the substance is exuded by the 

 plant on being punctured by the insect's proboscis, 

 or is in the nature of an excrementitious deposit on 

 the surface of the leaf We have heard both these 

 views expressed, but on inquiry it appeared that 

 our informants were merely stating what they 

 supposed to be the case, and not what they had 

 ascertained by actual observation. Reference to 

 half a dozen text-books has failed to show which of 

 these explanations is the right one, but, fortunately, 

 we are not without an authoritative statement on 

 the subject. The late Professor Westwood, in his 

 Introduction to the Modern Classification of 

 Insects, writing of the order Homoptera, the 

 members of which he describes as having a 

 convex body, with short antennae and four wings, 

 entirely membranous and deflexed, the mouth 

 arising from the under and hinder surface of the 

 head, the mandibles and maxillae enclosed in the 

 labium, proceeds to deal with the family CercopidcB, 

 the species of which are constantly found amongst 

 plants, upon the juices of which they subsist by 

 introducing their rostrum into the stems or leaves. 

 They belong to the same order as the AphidcB, but 

 to that section which has the whole of the upper 

 wings leathery. 



" One of the best known insects in this family," 

 he says, " is the Aphrophora spuniaria, a species of 

 small size, which frequents garden plants, the larva 

 and pupa investing themselves with a frothy ex- 

 crementitious secretion which has eiven rise to 

 various fancies. Cuculorum nascuntur spwno was 



