PARASITIC PLANTS. 191 



vancecl stage of growth, as the Gordius ? Is it a freak of 

 the latter ? Or, what of those which only live upon other 

 animals, such as lice ; are they the product of the skin \ Or 

 what of those which have to pass from the body of a lower 

 into that of a higher animal to undergo their final meta- 

 morphosis, and in which this succession is normal ? Was 

 such an arrangement devised by the first animal, or im- 

 posed upon the first by the second, or devised by physical 

 agents for the two 1 Or, what of those in which the 

 females only are parasites \ Had the two sexes a different 

 origin ? Did the males and females perhaps originate in 

 different ways ? 



I am at a loss to conceive how the origin of parasites 

 can be ascribed to physical causes, unless indeed animals 

 themselves be considered as physical causes with reference 

 to the parasites they nourish ; and if so, why can they not 

 get rid of them, as well as produce them, for it cannot be 

 supposed, that all this is not done consciously, when 

 parasites bear such close structural relations to the various 

 types to which they belong ? 



The existence of parasitic animals belonging to so many 

 different types of the animal as well as of the vegetable 

 kingdom is a fact of deep meaning, which Man himself can- 

 not too earnestly consider ; and, while he marvels at the 

 fact, let him take it as a warning for himself, with reference 

 to his boasted and yet legitimate independence. All rela- 

 tions in nature are regulated by a superior wisdom. May 

 we only learn in the end to conform, within the limits of 

 our own sphere, to the laws assigned to each race ! 



