The effect of food and water deprivation upon hippocampal rhythmic theta activity and heart rate were investigated in albino rats. With regard to hippocampal electrical activity, it was specifically intended in the present study to see whether frequency of theta wave would change with deprivation. The results of this experiment indicated that no uniform change in frequency of theta wave occurred during first and second days of deprivation. With longer (at least for three days) of deprivation, however, theta frequency tended to decrease for all Ss. Heart rate was found to decrease during deprivation as compared with during control sessions. These findings were discussed in terms of an activation theory (12) and hippocampal function (6, 7).

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Several effects of fighting behavior on feeding was studied in the guppy, Poecilia reticulata. The size of males' fish used in this experiment was from 15mm to 23mm. The fish was placed alone without food during more than 72 hours.
Experiment 1 : Two fishes were put together in one aquarium. And then the fighting behavior of them were observed in 30 minutes (Exp. 1-1). After the observation they were removed separately into each cell of the basket, which was divided into two cells with a glass, and were given Daphnia as the food of them. All the social behavior of them in each cell was noticed for 30 minutes (Exp. 1-2).
Experiment 2 : Exp. 2-1 was carried out in the same method as Exp. 1-1. All the social behavior of the fish was observed in the aquarium used in Exp. 2-1 (Exp. 2-2), in order to eliminate the effect of the glass (Exp. 1-2) on the fish.
The results obtained are as follows :
1) The fighting behavior of the fish was the most active in the first ten minutes, so that the social order were established between them (Exp. 1).
2) The total numbers of Daphnia eaten ascended in about ten minutes in each fish (Exp. 1).
3) The dominant fishes ate occasionally small numbers of Daphnia from 10 to 30 minutes. On the other hand, the subordinate ones took food little in the period (Exp. 1).
4) When 100 numbers of Daphnia were given in the aquarium, two guppies fed them at first, and then the fighting behavior was observed in the pair. The subordinate fishes were prevented from the feeding behavior by the fighting behavior of the dominant ones (Exp. 2).
5) The dominant fishes ate more numbers of Daphnia than the subordinate did, though there was no statistical significant difference between them (Exp. 2).

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The tool-using behavior in the ant-lions (the larvae of the Myrmeleon formicarius) was observed in detail and experimented analytically. This behavior is the throwing-up of sand by the ant-lions to capture the preys, namely, Formica japonica, Aphenogaster famelica and Lasius niger, if they try to escape out of the pits. In each experiment a new individual of these three species of ants was used. Several results obtained were reported in the present paper.
1) Six patterns, i. e., BC, BC, BCTC, BCTC, TC and TC were discriminated in the feeding behavior. Excepting two patterns, BC and BC, each one of them includes the sand-throwing-up or tool-using behavior.
2) The tool-using behavior is resulted in the ant-lions as a kind of direct or indirect chain responses following the completion of nest building. The sign stimulus in this tool-using behavior is a kind of mechanical stimuli, that is, the extremely faint pressure given by the ant to the side wall of the pit. The tool-using behavior is determined by three factors : 1) the preceding of the biting behavior, 2) the bodily condition (the elongation of sand-throwing-up distance as a result of bodily growth) and 3) the position of the prey (within or beyond the capturing area).
3) When the value of a ratio of the diameter of the pit to twice the length of the the generating line, D/2L cos α (the angle between D and L), is 0.654 in pattern B of the ant-lions and 0.697 in pattern C, their tool-using to prey the ants is most effective.
4) The rate of capturing the prey by the ant-lion increases with age. It is apparently found that the increase of this rate depends upon both the enlargement of the capturing area with the increase of size of the pit and the lengthening of the sand-throwing-up distance as the result of growth of the bodily mechanism.
5) The sand-throwing-up has the survival value next to the biting behavior in capturing preys.
6) This sand-throwing-up is a kind of instinctive tool-using behavior. But the older the ant-lion grows, the more effective the tool-using behavior becomes, because the animal has many chances of sand-throwing-up with age. In other words, the sand-throwing-up is seemed to include a kind of learned behavior. As some valid evidences we can point out increase of the rate of capturing preys caused by both a few sand-throwing-up and a small number of hits at the preys with age.

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This experiment was designed to test the relative efficiency of color and form as cue with which Japanes monkeys can learn matching to sample problems.
In the training periods, 4 Japanese monkeys were trained on simple matching to sample problems using stimuli shown in Fig. 1 (O) with a modified WGTA. A correction method was used. After criterion (more than 80% correct responses, 2 successive days) had been attained, monkeys were subjected to color-form cue dominance test.
In the test periods, each subject received 96 trials a day for 5 days. A test trial was inserted every 4th trial. On a test trial, an ambiguous stimulus was presented as a sample and it yielded two separate solutions arrived at by using two independent cue dimensions. For example, a sample object might be a red ball and choice objects might be a red ball and blue green cross on an original training trial, then the red ball as a sample was changed to a blue green ball, or two choice objects to a blue green ball and a red cross. A food reward would be obtained either by a color response or by a form response (blue green cross or red ball in the former case).
The learning processes of the animals on matching to sample problems are illustrated in Fig. 2. The results of testing (Table 1) did not show the color dominance found by YAGI et al. (7) on ambiguous oddity problems. It was assumed that this discrepancy was due to the procedural differences in oddity problems and matching to sample problems. In matching, a trial is split into two phases : sampling and choice. And touching the sample objects during sampling may increase the tendency to use form cues.
Based on this assumption, the same test was executed with all the stimuli being covered with transparent plastic covers not to allow the animals to touch the objects directly. The data (Fig. 5, Table 2) showed the color dominance and confirmed our assumption.
Subsequently, monkeys were given simple matching to sample problems which consist of the possible combinations of unidimensional stimuli shown in Fig. 3 with and without plastic covers. In these test, the transfer effect from the previous matching to sample problems was observed (Fig. 6).

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[in Japanese]

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