486 PROGRESS OF SCIENCE IN THE CENTURY. 



ently breaks into two great divisions {Homo mon- 

 golicus and Homo americanus) ; (IV.) between the 

 negro and the Mongolo-American boughs the main 

 stem passes upwards, developing a generalised Cau- 

 casic type (Homo caucasicus), which also at an 

 early date ramifies into three great branches, filling 

 all the intervening central space, overshadowing the 

 negro, overtopping the mongol, and shooting still 

 upwards, one might say, into almost illimitable 

 space. Such is the dominant position of the highest 

 of the Hominida?, which seems alone destined to a 

 great future, as it is alone heir to a great past. All 

 the works of man worthy of record have, with few 

 or doubtful exceptions, emanated from the large and 

 much convoluted brain of the white Homo caucasi- 

 cus.'^' 



EVOLUTION OF LANGUAGE. 



For millions of years the silence of nature was 

 broken only by the ^^ inanimate " voices of wind and 

 wave, of thunder-clap and cataract. There was no 

 voice of life, until this began among insects, and 

 at a much later stage once again among amphibians. 

 The croaking of frogs is effected by a mechanism 

 (of larynx and vocal cords) essentially similar to 

 that of the prima donna's song. Even a brief study 

 of the vocal sounds made by birds and mammals 

 shows that certain sounds are restricted to certain 

 occasions and have a certain meaning. They express 

 particular emotional states, and they often indicate 

 the discovery of danger or of food. In this sense, 

 there is no doubt that the young chick or the dog 

 has a few definite words. That fairly definite in- 

 * From Keane, p. 226. 



