408 NOTES OF A BOTANIST CHAP. 



that kind of mite is confined to a higher and cooler 

 zone, and never descends to the warm zone of the 

 Red Bark. 



Let it be observed that these scrobicules, although 

 I have no doubt of their origin by insect-agency, are 

 quite as good and permanent a botanical character 

 as many others as the sacciferous leaves of Tococa, 

 for example. [What a vast length of time, com- 

 pared with man's brief life, it must have taken to 

 impress a character of permanence on the latter 

 character and render it hereditary ! Probably a 

 period far longer than those we choose to designate 

 "historical" or "bronze" or "stone." The in- 

 imitable researches of Mr. Darwin have rendered it 

 (to my mind) almost certain that many of the devia- 

 tions from symmetry in the form and direction of 

 the parts of a flower have been brought about by 

 the direct mechanical agency of insects ; and that 

 the origin of every obliquity, unequal-sidedness, and 

 so forth, in any organ of a plant, is to be sought in 

 the action of forces not only internal, but also 

 external to the plant itself.] In this wonderful 

 ' life," which exists only through perpetual change, 

 every equilibrium is unstable, and even what we call 

 "permanence" is but a transitory state. 



In fine, the list of structures which I have above 

 assigned to Ant-agency might no doubt be very 

 much extended, and perhaps more satisfactorily 

 classified. I have described only what I have seen 

 with my own eyes and noted down on the spot ; and 

 corroborative specimens of all the plants mentioned 

 exist in the Royal Herbarium at Kew, by means of 

 which the accuracy of my account of the structures 

 inhabited by ants may at any time be tested. 



