388 BOTANICAL GAZETTE . [DECEMBER 
suggested that there are other potential sources of food in Cecropia. 
Thus, vON [HERING and FIEBRIG maintain that the imagines feed 
upon the succulent medullary tissues in immature internodes. It 
is true that the ants cut away the softer portions of the pith down 
to a hard, smooth peripheral layer of medullary tissue, but I found 
no evidence to indicate that this is not purely a process of house 
cleaning, such as occurs in many ant nests. In the moist, warm 
interiors of plants, ants have to contend with luxuriant growths of 
fungi which obstruct the cavities and interfere with the brood, 
unless they are held in check. The ants trim away the hyphae 
and cut back the substratum upon which these organisms tend to 
grow. Fiepric records, having seen Aztecas busily engaged in 
excavating the pith, and in casting fragments of medullary tissue 
from their entrances, but such observations cannot be interpreted 
as evidence that the ants actually feed upon the tissues that they 
are removing. 
Most students of the myrmecophytic species of Cecropia have 
found coccids associated with the ants which inhabit the fistulose 
stems. Their presence has been variously interpreted. BELT, 
MU ter, and ULE consider that they are tended by the ants which 
wee on their sugary exudations, but Freprie states that the insects 
“in keinen direkten Verhiltnis zu diesen Ameisen stehen.” 
Having found a very close and significant relation between ants and 
coccids in most Ethiopian ant-plants, I devoted particular atten- 
tion to the investigation of their behavior in C. angulata. I did 
not succeed in finding a single large, ant-inhabited specimen which 
did not contain numerous coccids. When a tree is split open the 
ants are as solicitous for the welfare of the coccids as they are for 
that of their eggs, larvae, and pupae. They seize them in their 
mandibles and carry them about until some unopened portion of 
the plant is found where they may be deposited in safety. In 
artificial nests, the workers spend hours in tending and stroking the 
coccids, and in feeding upon their sugary exudates. In view of 
these facts, it cannot be doubted that the miniature milch cows are 
an important source of liquid carbohydrates for the ants. 
As in many of the African myrmecophytes, the ants excavate 
pits in the walls of their domatia which enable the coccids to reach 
