502 CASUALTIES OF VEGETABLES. CHAP. XII. 



great care of Providence for the preservation of the 

 species, but points out also the efficient cause. 



SUBSECTION X. 



Caused Contortion. The leaves of plants are often in- 



puncture jured by means of the puncture of insects, so as to 



of insects, j R( j uce a sort o f disease that discovers itself in the 



contortion or convolution of the margin, or wrinkled 



appearance of the surface. 



As occur- The leaves of the Apricot, Peach, and Nectarine, 

 16 .are extremely liable to be thus affected in the months 



^ ^ une an ^ J^Y' The leaf that has been punc- 

 tured soon begins to assume a rough and 

 wrinkled figure, and a reddish and scrophulous ap- 

 pearance, particularly on the upper surface. The 

 margins roll inwards on the under side, and en- 

 close the eggs which are scattered irregularly on the 

 surface, giving it a blackish and granular ap- 

 pearance, but without materially injuring its 

 health. 



Of the In the Vine the substance deposited on the leaf is 

 ne> whitish, giving the under surface a sort of a frosted 

 appearance, but not occasioning the red and scro- 

 phulous aspect of the upper surface of the leaf of 

 the Nectarine. 



Poplar, In the Poplar the eggs when first deposited re- 

 semble a number of small and hoary vescicles con- 

 taining a sort of clear and cojourjess fluid, The 



