1922] BAILEY—ANT-PLANTS 385 
entrances in portions of the internodes which are not provided 
with preformed depressions. 
It may be argued that in C. angulata the whole groove has been 
modified as an adaptation to ants. Such an assumption is not 
warranted, however, when important facts in the anatomy of the 
non-myrmecophytic C. sciadophylla var. decurrens are taken into con- 
sideration. Although this species is not inhabited by Aztecas, it is 
provided with more tenuous and highly specialized diaphragms than 
is C. angulaia (text fig. 8; fig. 2). The internodal groove is very 
Fic. 8.—Prostomata or internodal diaphragms of various species of Cecropia: 
4,C. indenobus, after Scummper; B, C. sciadophylla var. decurrens; C,C. angulata; X4. 
broad and deep, and the diaphragm, which is entirely devoid of 
tough tissues and secretory vessels, is composed of extremely thin 
layers of delicate parenchyma. Such facts as these suggest that 
the so-called prostoma of C. adenopus, and of other myrmecophytic 
species of Cecropia, is not an adaptation for attracting ants, but 
is merely a structural peculiarity, produced by. the pressure of the 
axillary bud, which is utilized by the ants in their parasitism upon 
the plants 
Feeding habits of guest ants 
The Asteca colonies are initiated by young fecundated queens 
which cut entrances into the fistulose stems of juvenile plants. 
Although I examined hundreds of plantlets of C. angulata, none 
