290 CARL W. BOCK 



subjective positive after-image, and did actually re-discover the 

 so-called positive after-image of long duration because he had 

 noted the final accentuation of groups. Specifically he noted 

 that certain animals often accompanied the final beat of a group 

 by a simultanous beat with another member of the body. Thus 

 certain bears that made peculiar up and down movements of 

 their bodies accompanied the last of the movements by simul- 

 taneously slapping the walls of the cage against which they sup- 

 ported themselves with one of their front paws. This slap, or 

 movement corresponds, so Swindle believes, to the final accent 

 as shown in the above figure except that in the figure the extra 

 movement is shown as made by the same body member and not 

 by an extraneous one. The writer has made similar observa- 

 tions. Generally the last beat is accented. Ordinarily he could 

 not observe however that the final beat of a group was accom- 

 panied by any particularly pronounced movement of any other 

 body member. As a matter of fact every beat of the finger was 

 accompanied by slight movements of every other part of the body 

 and very close observations showed that these slight movements 

 were not necessarily mechanical effects of the moving arm or 

 finger, but actual physiological contractions. These movements 

 were given in the same tempo as that of the main activity, and 

 they could be well felt by simply grasping the limbs in question 

 by the hand and feeling the contractions. And generally the final 

 accent of the mam activity was accompanied by a slight in- 

 crease in the amplitudes of the accessory-movements. The writer 

 wishes here merely to call attention to the principle of the final 

 accent and such other observations which he made in this connec- 

 tion as well as those of Swindle. They are theoretically very 

 important and their discussion will be referred to in a separate 

 section of this study. The fact of the final accent establishes the 

 significance of the discussion of figure 2, and therefore the con- 

 stitution of the 46 group above. Consider figure 2: 



Figure 2 is entirely similar to figure 2 except that the separate 

 components of the 46 group are not as well delineated as in the 

 preceding figure. Consider figure 3. 



