190 Journal of Comparative Neurology. 



from the involuntary or natural attention, the best instance of 

 which is an animal of prey watching for an occasion to pounce 

 upon its victim. In a state of attention every sentiment is di- 

 rected toward one point which is the object of the intended 

 movement. 



The problem may be proposed how the unity of conscious- 

 ness can be attained in an organism in which all the various 

 parts, upon a crude examination, appear to be double. In at- 

 tempting to solve this problem we would say, first, that the 

 vario*us parts of the brain are by no means double. The center 

 of language has its seat in the left hemisphere and is apparently 

 unrepresented in the right hemisphere. It is most probable 

 that each arm is represented twice in the cortical substance, 

 once in each motory centre of the hemispheres. The right 

 hand is best represented in the left hemisphere, and the left hand 

 in the right hemisphere. But it appears that they are not un- 

 represented in either. Professor Goltz of Strasburg possesses a 

 monkey whose left hemisphere has been removed and we should, 

 according to the commonly accepted view, expect that she would 

 no longer use her right hand in seizing food. Professor Goltz 

 when showing me this monkey, called my attention to the fact 

 that she nevertheless grasps tidbits offered her with her right 

 hand. This seemed strange and contradictory to the localisa- 

 tion theory of Hitzig and Munk, but Professor Goltz explained 

 the case by stating that the monkey after the removal of her 

 left hemisphere actually used her left hand in preference to the 

 right hand, but whenever she did so he gave her a slap on the 

 left hand until she began to use her right hand. This repeated 

 experiment produced at last a habit in her of using the right hand 

 at once, which, according to Professor Goltz's own statement, 

 requires a greater effort, on her part as the right hand has re- 

 mained weaker than the left hand ever since the removal of the 

 left hemisphere. This beautiful experiment of Professor Goltz 

 does not refute Professor Hitzig's localization theory, but only 

 corrects it by proving that the limbs of both sides are repre- 

 sented in both hemispheres ; in the opposite stronger than in 

 that of the same side. The same seems to be true of the centre 



