300 Scientific Proceedings^ Royal Dublin Society. 



open, and the auLs were removing the seeds, without the hairs, to their 

 nest. 



It is probable tliat these seeds are removed and stored for food, those that 

 are not eaten germinating, though there is no evidence that the seeds are 

 stored in one particular place, as the young seedlings are found scattei-ed along 

 the runs at considerable distances from the parent plant. I have several 

 times seen the seedlings growing through holes in the pitchers of D. rafflesiana ; 

 if the ants intended tlie seeds to germinate, they would hardly choose so 

 unsuitable a place. 



The supposed preference of B. rafflesiana for decaying trees may be really 

 the preference of the Iridomyrmex, wliich often makes its runs along dead 

 brandies, and uses the dry wood of those branches in the material of its runs 

 and nests. Sucli branches are not advantageous to Dischidia, as they break 

 off all the sooner when burdened with the weight of the pitchers and their 

 contents ; broken off branches carrying clusters of pitchers may be often seen 

 hanging suspended by tlie twining slioots of the Dischidia. 



The ContenU of the Pitchers of D. rafflesiana. 



While the older pitchers of D. rafflesiana nearly always have nests of 

 Iridomyrmex, the younger frequently contain only pitcher-roots. The nests 

 are built round the roots, the roots branching most freely wliere the nest- 

 material is abundant ; root hairs are usually not developed unless the roots 

 are in contact with the nest-material. 



A microscopical examination of the nest-material showed it to be 

 composed of clay mixed with bits of wood and otlier vegetable matter ; 

 occasionally fragments of branched, septate, fungal-hyphee were seen, and 

 once or twice some two-celled spore-like organisms. I made several attempts, 

 by keeping the material constantly damp in the dark under a glass, to 

 develop these liyplite, but never obtained any growth. 



Most observers have mentioned water as a content of these pitchers. I 

 had in previous years, during the dry season, opened pitchers without finding 

 water. Last year (1911) I systematically examined a number of pitchers a few 

 days after rain or while rain was falling, not selecting the pitehei's in any 

 way, but examining all witliin reach. 



