510 PHYSIOLOGY CHAP. 



corpora quadrigemina were absent. The child only lived a day 

 and a half. During this time it cried and showed signs of dis- 

 comfort, and when the skin was pinched, its cries and associated 

 movements of the lirnbs became more marked. Heubner observed 

 a human anencephalous infant that lived sixteen days, and behaved 

 exactly like a normal child of the same age. 



Normal new-born infants who have no intellectual psychical 

 activities cry, like Goltz' dog, when they are hungry or distressed ; 

 after being suckled and laid comfortably to rest they become quiet 

 and sleep. Dements, again, and low-grade microcephalic idiots are 

 comparable to the brainless dog; they are men without a brain, 

 who have no intellect or memory, but who nevertheless possess 

 sensory and motor capacity. Their special senses persist; they 

 experience sensations of hunger and thirst, and their acts are 

 directed to satisfying their needs ; they react to painful sensations 

 by movements of defence and cries of distress. It is therefore 

 evident that profound dementia, i.e. the complete absence of the 

 higher psychical faculties, does not necessarily imply loss of the 

 lower faculties. 



In monkeys, too, the fore-brain has been removed by Karplus 

 and Kreidl (1912) at the Physiological Institute of Vienna. 

 Macacus rheus bears the complete extirpation of one hemisphere 

 well. In a few hours it is able to assume the sitting posture in 

 its cage and to feed itself by means of the limb of the side operated 

 on. The whole of the opposite side shows grave disturbances in 

 movement and sensation, but a large part of these disappear in 

 the course of a few weeks. For months, however, the monkey 

 feeds itself almost exclusively with the hand of the side operated 

 on ; only when this is prevented does it use that of the opposite side. 



After the extirpation of the second hemisphere the results were 

 less successful ; only two monkeys survived for two weeks. The 

 extremities, which were paretic after the first operation, were 

 moved more freely and frequently after the second than the limbs 

 of the other side. The monkeys were alternately in a state of 

 waking and sleeping; the sleep lasted longer than the waking 

 period, during which they opened their eyes, moved, and reacted 

 freely to various stimuli. The movements of the head and eyes 

 are normal, those of the limbs much altered. One of the animals 

 a few days after the second operation succeeded in assuming the 

 sitting posture with its head erect, in eating with the hand that 

 had become paretic after the first operation, and in suspending 

 itself for some minutes to the bars of the cage, after which it shut 

 its eyes, bent its head, and relapsed into the sleeping state. 



Light stimuli caused the pupil to contract but produced no 

 other reaction. Strong auditory stimuli roused the monkey 

 from sleep, and when awake it produced not only reflex move- 

 ments of the ears, but also movements of the head and of the 



