326 Heredity. 



We are now, after a long circuit, able to resolve our problem 

 and to reach a conclusion. It may be remembered that we have 

 already endeavoured to show that for every habitual mental state 

 there is an habitual state of brain, and thence deduced the 

 fact that for the mediaeval state of semi-hallucination there must 

 have been a corresponding cerebral state, and another for the 

 precise, accurate mind of the eighteenth century. This transition 

 was effected by a slow progress that is to say, that education and 

 culture produced in the mind and brain trifling though stable 

 modifications, which were handed down, preserved, and accumu- 

 lated by heredity. Thus was formed an average intellectual con- 

 stitution, more and more able to conceive abstract ideas, and 

 consequently less and less able to perform mental operations by 

 means of visions and impressions. 



It has often been observed that among the inferior races children 

 who are sent to school, or whom an effort is made to instruct, at 

 first show a surprising facility, but this suddenly ceases. Thus, 

 the Sandwich Islanders have an excellent memory, learn by 



' One night, before matins, I saw before me, at the foot of my bed, an ugly 

 little monster in human form. He appeared to me to be of middle stature, 

 with skinny neck, slender figure, deep-black eyes, narrow, wrinkled fore- 

 head, flat nose, wide mouth, swollen lips, short, weak chin, goat's beard, 

 narrow pointed ears, unkempt, lank hair, teeth like those of a dog, sharp pole, 

 prominent chest, a hump on his back, pendant buttocks, and dirty garments. 

 He seized the side of the bed whereon I lay, shook it with fearful violence, 

 and kept saying : You have not long to remain here. Suddenly I awoke in 

 alarm. ... I leaped out of my bed, ran to the monastery, threw myself 

 at the foot of the altar, and there remained prostrate for a long time, frozen stiff, 

 as it were, with fright. ' R. Glaber, Book v. ch. i. 



He saw the same devil on two other occasions. We find all the horror of 

 nightmare in the following narrative from Guibert de Nogent : 



1 On a certain night, having been awakened by my sufferings it was in 

 winter, I believe as I lay in my bed, thinking I should be in greater safety 

 owing to the proximity of a lamp which gave a bright light, lo, all of a sudden, 

 amid the profound silence of the night I thought I heard several voices from 

 above. At the same moment my head received a shock as though I were 

 dreaming ; I lost the use of my senses, and thought I saw a certain dead person 

 appear, the while some one shouted out that he had died in the bath. Alarmed 

 at this apparition, I leaped from my place and uttered a cry ; I saw that my 

 lamp was out, and amid the fearful gloom discerned the demon, in his proper 

 shape, standing erect, and beside the dead man.' Guibert de Nogent, i. xv. 



