CHAPTER XXIV 



ANTS AS MODIFIERS OF PLANT-STRUCTURE 



[THE paper which forms the greater part of this 

 chapter was written during the first few years after 

 Spruce's return to England, and at a time when 

 he had probably not seen, and had certainly not 

 carefully read, the Origin of Species, the teachings 

 of which at a later period he fully appreciated. At 

 this period he accepted as did almost all natu- 

 ralists, including Darwin himself what is termed the 

 heredity of acquired characters, such as the effects 

 on the individual of use or disuse of organs, of abun- 

 dant or scanty nutrition, of heat and cold, excessive 

 moisture or aridity, and other like agencies. But 

 in the paper here given he went a step beyond this, 

 and expressed his conviction that growths produced 

 by the punctures and gnawings of ants, combined 

 perhaps with their strongly acid secretions, con- 

 tinued year after year for perhaps long ages, at 

 length became hereditary and thus led to the curious 

 cells and other cavities on the leaves and stems of 

 certain plants, w r hich are now apparently constant in 

 each species and appear to be specially produced for 

 the use of the ants which invariably frequent them. 



This paper Spruce sent to Darwin, asking him 

 to send it to the Linnean Societv if he thought it 



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