A New Ficld-iiiOHSC in Japan. 
53 
road-sides directly exposed to sun-shine ; and moreover even on a ])lain 
farm on whicli various stuffs of halms, stalks or roots of tlie farms are piled 
up. The nests are constructed in an oval hollow, excavated usually at the 
depth of five to seven inches below the ground. Its walls are provided with 
one or more opening, which communicate with tunnels running in various 
directions and extending to various distances, where the mice may be able 
to procure their food. These tunnels open at various distances to the 
surface of the ground by roundish holes, which serve as a clue to the general 
direction of the tunnels. The tunnels extend as far as where the food plants 
are to be detected ; and close to the wheat, tea, mulberry and other farms 
which are preferred by the mice, there open usually one or more holes. In 
the case of wheat, the mice come out to the surface from the holes opening 
close by, cut off the stalks or leaves at a height of less than an inch above 
the ground, and eat them on the spot, or else they carry them to their nests; 
thus the holes and newly cut stalks or leaves of the wheat indicate, without 
doubt, the presence of the mice. But in the case of tea and mulberry trees, 
the mice do injury only to the root by gnawing the cortical layer leaving 
series of traces of their teeth on the surface of the woody layer (Fig. 5. 
ri. IX.). 
The nests (Fig. 6. Pi. IX.) are generally oval (length about 22 cm., 
breadth 14 cm.), or nearly roundish, more or less flattened, consist of a single 
chamber. The materials employed for the construction of the nests arc 
generally fine strips of straw or fibrous roots of various plants. The inner 
layer of the nest consists of a much finer and softer stuff than the outer. 
The nest is provided with the same number of openings as the hollow within 
which it lies, thus giving the mice free passage towards the tunnels. Close 
to the hollow in which the nest lies, is excavated another small chamber or 
hollow mainly used for preserving food. The principal food stuffs, so far as 
I could find in the store chamber, are strips of the roots of tea or mulberry 
trees, roots of Lappa major, GjErtn., Daucus carota, L., the stalks or leaves 
of the tobacco plant, ears of the rice plant and others. The roots are cut 
off nearly to an equal length and piled up horizontally in a regular manner 
in the store chamber ; and especially the ears of the rice plant are equally 
cut off to the length of four to five inches, and then they arc piled up 
