440 . Mound-Making Ants of the Alleghentes. [July, 
was covered with insects. The black and red masses whirled in in- 
distinguishable mazes, producing a very perceptible buzzing sound 
by their rapid movements. Even for several feet beyond the hill, 
on the opposite side, the excitement extended, and was manifest 
with almost equal rapidity. 
Tree-paths.—The word tree-path, as used above, perhaps needs 
a briefexplanation. It was observed that the ants ascending and de- 
scending the trees invariably kept to a beaten track, two or more 
inches in width. In many cases this track or tree-path was stained, 
the entire length of the trunk, a brownish-yellow color, caused 
doubtless by the formic acid which the ants secrete. The position 
of these tree-paths is determined by the situation of the hill to 
whose domain the tree belongs, for each community has its own 
special feeding grounds upon which intrusion is rarely if ever 
made. The tree-path is located habitually upon that part of the 
trunk which directly faces the hill. This was verified by observa- 
tions upon a very great number of trees. 
Winter Habits—There are several inferences, more or less con- 
clusive, concerning the winter economy of the fallow ant which 
we may draw from the facts. First, the ants dwell within their 
formicaries during winter, and make no attempt to modify the 
surface surroundings. Second, the vast majority of the com- 
munity, together with the fertile queens, larvae and cocoons oc- 
cupy the underground galleries. This appears from the fact that 
but one young queen and comparatively few workers of the 
various classes were found in the hill galleries. Third, the com- 
position of the mounds is such as to ensure, in the central parts, 
a good degree of protection against ordinarily severe winters for 
the few ants that occupy them. Fourth, the vitality of the ants 
is sufficient to keep them active within the hills during all ordi- 
nary seasons. Fifth, it is yet more evident that the occupants of 
the underground galleries are not torpid during ordinary winters, 
if ever, but exist in a state of considerable activity. Finally, it 
would appear that the ants are able to spend the winter in the 
active state without regular and ordinary supplies of food. 
I do not advance this last opinion with any great degree of 
confidence. The mysteries of the underground galleries still veil 
the facts that would solve the question completely. But all the 
known facts point to the above inference. I had thought that 
the tufts of grass which grow upon many hills, and which evi- 
