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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 w^hich 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, which 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 Society if he thought it 
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