POPLAR. 241 



called propolis, which they employ not only in finishing 

 the combs, but in rendering every chink or orifice 

 impervious to the weather, or to the insidious attacks of 

 their enemies. 



Insect tribes resort to poplars of different species, and 

 become identified with their favourite trees. Among these, 

 the nocturnal Phalana gemma prepares for herself a nest 

 in October, when about to undergo a transformation, by 

 enclosing herself between two leaves, having previously 

 united the edges by means of numerous threads. A 

 delicately effused white web may also be observed on our 

 leaves in spring and summer. This web is produced by 

 the Erysiphe adunca before arriving at maturity, considered 

 as the most beautiful of the genus, and resembling little 

 sparkling stars, when examined under a pocket magnifier. 



Our small family contains only three members, the 

 black, the white, and the trembling. 



The first, of tall growth, with smooth bark, affects rivers 

 and wet shady places, equally with woods and plantations 



