PAriASlTES OF PLANTS. 13 



who can solve these mysteries, and lay the 

 whole facts of such cases before them. 



It is the design of the author to unfold 

 some of these secrets which have hitherto been 

 so seldom, if at all, described in popular lan- 

 guage. Attention will be principally directed 

 to those blights which are the work o^ parasites, 

 both fungi and insects. It will be proper, 

 therefore, first, to define what is meant by the 

 term parasite. It is derived from the Greek 

 word TrapdcriroQ, (parasitos,) meaning one that 

 lives at the expense of another. From this 

 derivation, it will readily be seen that the term 

 is appropriately taken by naturalists to signify 

 that whatever they so name lives at the ex- 

 pense of some other thing. We should there- 

 fore define the parasite of a living organized 

 substance, as another living organized sub- 

 stance produced in and owing its subsequent 

 support to the former. The parasite of a 

 vegetable is another vegetable existing under 

 these circumstances. Parasites of plants are 

 of two kinds, the leafy and the leafless. Those 

 that have leaves, of which the mistletoe is a 

 familiar example, avail themselves of the 

 ascending sap of the plants to which they are 

 attached, elaborating it in their own leaves. 



