32 Flowers and their Unbidden Guests. 



from destruction by grazing animals ; just such a 

 portion in fact as is necessary in order that the further 

 developmentary processes, which in the total absence 

 of leaves would be completely arrested, may be carried 

 on. Thus much being safe, the remainder is left to 

 the tender mercies of animals. The very existence of 

 herbivorous animals would plainly be impossible, were 

 all the leaves of aU plants rendered inaccessible to them 

 or uneatable. 



It does not, however, come within the scope of this 

 treatise to deal with these relations between plants and 

 animals in detaiL In making the above remarks I 

 merely wish to indicate that those structural arrange- 

 ments by which foliage is preserved, or rather in part 

 preserved, from animals, are not without significance 

 as regards the flowers; inasmuch as these can only 

 develop themselves out of material which has first been 

 fabricated by the leaves. 



B. — Protective A^^liances of the Flowers against 

 Unbidden Quests. 



If it be of importance to a plant to have some of its 

 leaves protected from animals, of still greater importance 

 is it that this shall be the case with its flowers. It was 

 therefore to be expected that the flowers, which are 

 constructed out of leaves, should be even better protected 

 than the leaves themselves. Plants, whose flowers 



