RELATIONS OF ANTS TO VASCULAR PLAXTS. 



39 



internodes, while the Miillerian bodies, though continually formed anew 

 as they drop off or are carried away by the ants, may have an excre- 

 tory or some other nonmyrmecophilous function, for aught that is 

 known to the contrary. The adaptation, therefore, has every appear- 

 ance of being on the side of the ant rather than on that of the tree. 

 This is also indicated by two other considerations : first, by the habits 



FIG. 178. Acacia sphaerocephala. (Schimper.) A, End of branch showing 

 pairs of hollow thorns which are inhabited by ants (Pseitdoniynna) ; .r, openings 

 of nests ; B, leaf of same plant ; v. nectary on upper surface of petiole ; C. tip of leaf- 

 let enlarged showing Beltian body. 



of the Azteca, which seems to have taken up its abode in the Cccropia 

 within comparatively recent times, since it has not abandoned the con- 

 struction of large fusiform carton nests like those produced on the 

 branches of trees by many other species, although the cavities of the 

 Cecropia seem to be better adapted to long cylindrical nests or would 



