XXIV ANTS AND PLANT-STRUCTURE 387 
among his papers till now. Spruce was very sensi- 
tive to criticisms of his writings by persons who 
had not the same knowledge that he possessed ; 
but in this case I think it probable that he himself, 
later on, recognised the incompleteness of the evi- 
dence. A year and a half later he corresponded 
with Mr. H anbury on the subject, and he was 
evidently seeking for more information. I there- 
fore now print his paper in full, with a few omissions 
of unimportant details or digressions, giving the 
passages objected to within square brackets. It 
will be seen that they involve very slight alterations, 
in no w^ay affecting the facts or observations of the 
paper itself That he intended to modify and en- 
large the paper may perhaps be concluded from the 
fact that the paper cover in which the MSS. was 
kept contains in pencil two alternative titles, both 
less dogmatic than that on the paper itself. They 
are as follows : — 
(i) "On Changes in the Structure of Plants 
produced by the Agency of Ants." 
{2) "On Structures formed in Living Plants by 
Ants, which apparently become permanent 
in the Species." 
The paper here follows, and I shall at the end. 
adduce a few additional facts which will serve as a 
partial reply to the questions put by Darwin. ] 
