1. Behaviour patterns of a green frog, Rana nigromaculate, were observed at two small pools on the campus of the Kyushu University, from July to September, 1955. Individuals were marked by clipping their toes off, and also by tying colored vinyl strings to their bodies. 2. It was observed that most of the individuals stayed at the pool area for a long period. In the daytime, they rested in the shallow pits burrowed by themselves in the poolside, but at night, they left these pits for foraging. The home range of an individual was restricted to a small portion of the waterside of the pool. Early in the morning, the individuals returned to the sites near the resting places of the previous day, and some of them were observed to occupy the same pits of the previous day (Fig. 2). 3. In many cases, the home ranges of the individuals overlapped each other, but no aggressive or other repulsive behaviors were observed. Therefore, it may be said that this species does not hold territory at least in the non-breeding season. 4. The resting sites of an individual were not distributed at random around a pool, though it was a small one. Instead, it was observed that each individual had its own favorite place for resting (Fig.3 and Table 2). Once an individual settled in a place, it stayed there for several days, keeping its home range nearby. Then it moved to a new place which was usually not far from the first place. Such movings were observed repeatedly in the pool area. 5. Twenty new individuals were introduced experimentally into the smaller of the two pools. The daily changes of components of the inhabitants in each pool after this treatment are shown in Fig. 4. This figure seems to suggest that the dispersion of the individuals during the rain was accerelated by the high density due to the artificial transplantation, though it had been inhibited by the drought continued for several days at the beginning of the experiment.
