

THE HEMISPHERES. 481 



of impressions or objects presented to it, and thus enables its possessor, 

 by comprehending and retaining new ideas, to profit by experience. 



II. The general result of injury, disease, or disorganization of the 

 hemispheres in man, especially affecting the gray substance of the con- 

 volutions, is a disturbance, diminution, or suspension of the intellectual 

 faculties. In these cases, among the earliest and most constant of the 

 morbid phenomena is a loss or impairment of memory. The patient 

 forgets the names of particular objects or of particular persons ; or he 

 is unable to calculate numbers with his usual facility. His mental 

 derangement is often shown in the undue estimate which he forms of 

 passing events. He is no longer able to appreciate the relation between 

 different objects and phenomena. He will show an exaggerated degree of 

 solicitude about a trivial occurrence, and will pay no attention to matters 

 of real importance. As the difficulty increases, he becomes careless of 

 directions and advice, and must be managed like a child or an imbecile. 

 Finally, when the injury to the hemispheres is complete, the senses may 

 still remain active and impressible, while the patient is completely de- 

 prived of intelligence, memory, and judgment. The constancy of these 

 results when the lesion is situated in the hemispheres, and the fact that 

 they often occur without being accompanied by any loss of sensibility 

 or motion, show the close connection between the mental powers and 

 the nervous action of this portion of the brain. 



The same connection is seen in the existence of congenital idiocy with 

 imperfect development of the brain. In many cases the immediate con- 

 dition upon which the idiocy depends is the small size of the brain as a 

 whole, particularly conspicuous in the cerebral hemispheres. The general 

 and special senses, and the activity of the nervous system at large, are 

 sometimes fully developed in these instances, while the intelligence 

 proper remains at so low a grade, that no improvement in the mental 

 operations is possible and teaching is almost without effect. 



This was the case, in a marked degree, with a pair of dwarfed and 

 idiotic Central American children, who were exhibited at one time in 

 the United States, under the name of the " Aztecs." They were a boy 

 and a girl, aged respectively about seven and five years. 



The antero-posterior diameter of the boy's head was only 4j inches, 

 the transverse diameter less than 4 inches. The antero-posterior diameter 

 of the girl's head was 4^ inches, the transverse diameter only 3| inches. 

 The habits of both, so far as regards feeding and taking care of them- 

 selves, were those of children two or three years of age. They were 

 incapable of learning to talk, and could only repeat a few isolated words. 

 Notwithstanding, however, their limited intelligence, they were remark- 

 ably vivacious and excitable. While awake they were in almost con- 

 stant motion, and any new object or toy presented to them immediately 

 awakened a lively curiosity. They understood readily the meaning of 

 those who addressed them, so far as it could be conveyed by gesticula- 

 tion and the tone of voice ; but they could not be made to comprehend 



