Ants and Mites 



istic swelling; though not in such a pronounced form as 

 was usual. He draws the obvious common-sense con- 

 clusion that this rare characteristic of a swollen petiole 

 probably owes its origin to the visits of ants continued 

 for untold generations, until it has become a charac- 

 teristic of the species. 



The well-known scientific society before whom the 

 paper was laid, asked him to take out these conclusions 

 of his, which were of course the really interesting and 

 valuable part of the paper. Spruce never did so, and it 

 has only appeared in a recently published book. 



It is difficult to understand why this course was 

 taken ; even if Spruce had been proved wrong by other 

 observations, his conclusions were a valuable piece 

 of evidence which could have been tested, by other 

 naturalists. 



But then and even to-day there is a dogma which 

 says that mutilations can never be inherited. Only 

 to-day, after forty years, there are but few who believe 

 it as firmly as was the case at that time. Spruce not 

 unnaturally seems to have been disheartened and dis- 

 gusted by this affair. Now of course we know of 

 hundreds of ant plants which not only shelter swarms 

 of ferocious ants but provide them with board as well 

 as lodging. 



Some of these ant-plants produce sugary secretions, 

 others << food-bodies," which contain proteids. The 

 reader will find much of great interest about ant-plants 

 in Bates' '< Naturalist on the River Amazon." 



Perhaps the most striking of these plants are certain 

 acacias which have huge swollen stipule-thorns which are 

 hollow and form the residence. A minute hole gives 

 entrance and exit to the ants. There is also the Imbauba 

 or Cecropia, which has hollow internodes. At one point 

 in the stem there is a very thin weak spot just towards 



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