576 W. T. JAMES 



the electrodes were connected to the secondary coil of a 

 Harvard inductorium. Only one battery, which was renewed 

 frequently, was connected to the primary coil. The break 

 shock method was used, in which the painful irritation is 

 avoided by means of a sliding contact switch which breaks 

 the electric circuit to the electrodes when the leg' is raised. 

 A diagram of the apparatus is shown in text-figure 85 (fig. 3). 

 The string operating the switch also moves the recording- 

 lever on the kymograph. 



The break shock method is preferable to shocking the ani- 

 mal every time since the behavior reaction thus elicited ap- 

 proximates that which would be observed under natural 

 conditions, for instance by the use of the water hose when 

 the dogs become too noisy in the kennels. In such a case, 

 the hose is turned on, accompanied by shouts of, ''Get in 

 the house", or, "Inside." The dogs run for shelter when 

 the water is turned on them, and after a few repetitions of 

 this procedure only the words are necessary to elicit the 

 reaction. In many cases even the sight of the kennel man 

 approaching the hose will quiet the dogs. This is a typical 

 case of conditioned avoiding reaction. In this instance a 

 movement is made to avoid an unpleasant wetting. The dogs 

 might be trained to do the same thing by means of a shock 

 or whip. 



For the most part, the clicker, sounding at the rate of 

 120 per minute, was used as a positive signal. If this had 

 been used in previous experiments, a whistle, buzzer, or bell 



PLATE 101 



EXPLANATION OF FIGURES 



1 Characteristic posture of one of the well balanced animals giving the con- 

 ditioned avoiding reaction. This animal is a bassethound-German shepherd F 2 . 



l! Position assumed by the Saluki, a hyper-excitable animal, in the conditioned 

 avoiding situation. The leg is held in a half flexed position during the interval 

 between signals in what would seem to be a "set" in preparation for a quick 

 avoiding response when the signal is applied. 



3 and 4 Characteristic postures of excitable animals of group B avoiding the 

 shock. The animal in figure 3 is a German shepherd; the animal in figure 4 

 is a Saluki. 



