xxvii] DR. SPRUCE 69 



protective to leaves in hot forests where such ants do exist, 

 it has not been acquired originally to provide the requisite 

 protection. 



" I much doubt the correctness of Mr. Belt's theory that 

 the ants which inhabit leaf-sacs protect the leaves from 

 leaf-cutting ants ; for the leaves of such plants are almost 

 invariably thin and dry ; whereas the Sauba always selects 

 leaves that are more or less coriaceous, and if it really 

 wanted the sacciferous leaves I fancy it would make short 

 work of their frail inhabitants. Besides, there are numbers 

 of Melastomes, allied to Tococa and Myrmidone, which the 

 Sauba never touches, although they have no protective (?) 

 sacs ; but it cuts up readily the coriaceous leaves of other 

 Melastomes, such as various Bellucias, Henrietteas, &c. 



"Richard Spruce." 



This letter was written in pencil lying on a couch, to which 

 he was confined the greater part of the day during the latter 

 years of his life, and I have much pleasure in printing it here, 

 because it serves to show my friend's acuteness of observation, 

 and the great interest he took, not only in the structure, but 

 in the whole life and nature of the plants he loved so well, 

 and in their relations to the animal world. I have no doubt 

 but that his objections to Belt's theory that the small stinging 

 ants protected the leaves of the trees or shrubs they inhabited 

 from the very powerful and destructive Sauba ants, are quite 

 sound, and that his many years' observations in the Amazonian 

 forests are to be trusted on this point ; yet I believe that 

 Belt was right in their being protective, and there are many 

 devourers of leaves that are as destructive as the leaf-cutting 

 ants. Shrubs which always had colonies of stinging ants 

 would probably be avoided by the tapir and by deer, while 

 they would almost certainly check the ravages of caterpillars, 

 locusts, and the large leaf- and stick-insects. 



There is another point that this letter illustrates : the 

 wonderful complexity and adaptability of organization of 

 all living things leading to that infinite variety of form and 

 structure, of colour and motion, which constitute the greatest 



