POPULAR SCIENCE 97 



vores first left the ground and took to the trees, the new co- 

 ordinated muscular actions and the use of sight as well as of 

 smell to recognise the food marked the first stage of progress. 

 This may have been continued by the catching of birds at 

 night with little assistance from the sense of smell, and by 

 the use of the four extremities independently of each other. 

 The sands present conditions for further progress. By watching 

 the crabs and sea-birds — trying to catch them perhaps — new 

 food might have been recognised by the sight alone, even if 

 it had no feathers and did not move. Touch may have been 

 used to examine the mollusc, and a small stone used to crack 

 the shell. The animal learnt that some shells were empt}'- and 

 others full. Much later curiosity was rewarded by the epoch- 

 making discovery that shells similar to those on the beach 

 were attached to the rocks, and that these were always worth 

 cracking with a stone. The hand and foot were then steadily 

 advanced towards perfection by the needs of the new food- 

 supply, and the skull was gradually poised on the condyles. 

 The new food-supply was handed on from father to son by 

 tradition, not by instinct, and the growth of the brain was 

 assured as soon as it had reached the point of thinking of 

 things that were out of sight. The instinct of the squirrel has 

 taught it to bore a small hole in a nut to see if it is worth while 

 going farther in the matter, and I am told that the baboons 

 steal tins of bully beef as readily as fruit or loaves of bread. 



If we suppose that protoman was social and had as good 

 a language as the baboons, the tradition would soon lead to 

 the elements of speech. It has recently been suggested that 

 sign language arose before speech, chiefly from the fact that 

 the same signs were common to all the North American Indians, 

 although their speech was quite different.^ Of course very 

 early human skulls have the bony markings for the muscles 

 of the tongue of a primitive type, and the view is widely held 

 that speechless man was quite a large animal. But when speech 

 began, the human race had not yet separated into the three 

 great divisions, and yet man was already right-handed, for the 

 speech centre is always on the left side of the brain. Thereafter 

 brain growth was accelerated and knowledge in a new sense 

 began. The consciousness that thoughts can be expressed by 

 words must have been a continuous stimulus to evolution along 

 the new path. The dawn of this consciousness forms the 

 turning-point in the education of the blind deaf-mutes. It was 

 very marked in the classical case of Laura Bridgeman. The 

 changes which ensued all appear to be very ancient, and they 

 are characteristic of all existing races as compared with the 

 apes. The head of the foetus was enlarged, the period of 

 ^ Evans, Anthropology and the Classics. 

 7 



