318 DR WALTER KIDD. 



still more opposed to that found in man, being even in certain 

 areas di7'ectly opposed to it. 



As to the aetiology of the slope found on the dorsal region, and 

 round the neural border of the axilla, it is not difficult to see a 

 force which acts for about one-third of man's whole life pretty 

 consistently in a manner calculated to produce it. In sleep, 

 man spends so much more of his time lying on his side, and 

 with his head more or less raised on a pillow, that this attitude 

 may be taken as the predominant one. Little reflection is 

 required to show one that the attitude referred to necessarily 

 tends to produce this slope on account of the tendency of the 

 body to slide downwards off the pillow, and this would produce 

 the upward slope of the hair. A similar result must also follow 

 from the attitude of sitting with the back resting against a 

 support. But the slope is not only upwards towards the head 

 but is inwards toward the vertebral column, until it reaches the 

 borders of the vertebral furrow, where it changes, and this slope 

 is also obviously afiected by the same attitude. Passing also to 

 the scapular and deltoid regions, one can see how the tendency 

 to slide off the pillow in sleep contributes also to the slope 

 described as existing. In certain hairy subjects who have 

 suffered a good deal from illness, necessitating much of the re- 

 cumbent position, I have seen greatly exaggerated upward 

 sloping of the hair on the dorsal region. I would submit that 

 the mechanics required for the production of a very unexpected 

 slope of hair are here ready to hand. 



As to the parting on the lateral aspect of the thorax and 

 abdomen of the neural and ventral streams, one can do no more 

 than make one suggestion which may throw some light upon its 

 production. The attitude in sleep referred to as the preponder- 

 ating one brings with it a position of the arm and forearm which 

 may influence this parting. The arm lies exactly in the posi- 

 tion of this parting line when the person is lying on his side, 

 i.e., the arm opposite to the side on which he lies. The line of 

 the arm follows this parting until the radiating whorl, described 

 as existing at the level of the umbilicus, is reached, and this 

 whorl corresponds closely with the position of the elbow joint 

 when the limb is slightly flexed. The forearm, if extended, 

 would also lie over that further portion of the parting line 



