206 ARBOREAL MAN 



astonishing features of a newborn baby. It is generally 

 known that a baby within an hour of its birth can support 

 its body weight by hanging with its hands for at least 

 ten seconds. One observer (Dr. Louis Robinson) has 

 recorded the fact that twelve infants under one hour old 

 supported themselves thus for thirty seconds, and that 

 three or four could hold on for almost a minute. When 

 li the child is between a fortnight and a month old, it can 

 support its body weight by its hands for a longer period, 

 some even being capable of hanging on for ^wQ_iIiii^^^tes, 

 but after a month the baby generally refuses to be tried 

 by any such test, and relaxes its grasp when any strain 

 is exerted upon its arms. 



The suspension of the body weight for even a minute 

 by a baby a fortnight old may not seem to be a very 

 astonishing feat, and yet it is quite as much as most 

 adults can do. The suspension for two minutes thirty- 

 five seconds which Dr. Louis Robinson records for a baby 

 of three weeks is a truly remarkable performance, since 

 it is longer than that possible for the average healthy 

 schoolboy, and far longer than that attainable by most 

 adults. 



This curious strength of the grasp and of the arms is 

 an obvious arboreal adaptation of the human baby. It 

 is the survival of the grip which enabled it to cling to 

 its mother, and to the branches of its arboreal home, and 

 as such it wanes in the human body after the first few 

 months of its life, and becomes still less when the power 

 of walking upright is fully acquired in infancy. 



