(65) 



R. CHODAT. LA VEGETATION DU PARAGUAY 



191 



Mais le fondateur de la théorie (Belt, 1. c. 1872, 1888, 221) dit, 

 a propos d'Acacia (belonging to the section Gummifera) « the 

 thorns when they are first developed, are soft, and filled with a 

 sweetish, pulpy substance ; so that the ant, when it makes an 

 entrance into them, finds its new house full of food. It hollows 



Fig. 325. — Acacias Cavenia Bert. On a sectionne jusqu'à son milieu et longitudi- 

 nalement la portion tige stipulifère (stipules divergeant horizontalement). On voit 

 ainsi la cavité qui contient l'œuf coupée en deux. Oross. 10 fois. Dessin de E. C. 



this out, leaving only the hardened shell of the thorn. Strange to 

 say, this treatment seems to favour the developement of thèse 

 thorn as it increases in seize, bulging out towards the base ; whilst 

 is my plants that were not touched by the ants, the thornes tur- 

 ned yellow and dried up into dead but persistent prickles. » 



