93 
1903-4.] Dr Munro on Man in the Palaeolithic Period. 
now, their origin and development are among the most obscure 
problems within the whole range of anthropology. 
In the address which I had the honour of delivering in 1893, 
as president of the Anthropological Section of the British Associa- 
tion for that year, I advocated the hypothesis that the origin of 
the higher mental manifestations of man was primarily due to 
the attainment of the erect attitude, which, by entirely relieving 
the fore-limbs of their primary function as locomotive organs, 
afforded him the opportunity of entering on a new phase of 
existence, in which intelligence and mechanical skill became the 
governing factors. With the completion of the morphological 
changes involved in the attainment of this attitude, the evolution 
of the present human form, with the exception of some remark- 
able modifications in the skull and facial bones, which will be 
subsequently referred to, was practically completed. As soon as 
bipedal locomotion became habitual and firmly secured on an 
anatomical basis, it does not appear that the osseous characters of 
the lower limbs would be sensibly affected by any subsequent 
increase in the quantity or quality of brain-matter. For example, 
the function of the femurs being henceforth to support a certain 
load, i.e. the entire weight of the body, it would not influence 
them in the least whether that load contained the brains of a 
fool or of a philosopher. The important and novel element which 
the permanent assumption of the erect posture was the means of 
introducing on the field of human life, was the use to which the 
eliminated fore-limbs were put. By substituting, for nature’s 
means of defence and self-preservation, a variety of implements, 
weapons and tools made with their own hands, the subsequent 
well-being of these novel bipeds became dependent on their 
ability to interpret and utilise the laws and forces of nature. 
As time went on they began to recognise the value of the faculty 
of reasoning as the true source of inventive skill ; and hence a 
premium was put on this commodity. In this way, stimulants to 
the production of new ideas and new inventions were constantly 
coming within the scope of their daily avocations, the result of 
which was a steady increase of human intelligence, and conse- 
quently of brain substance. Now, according to the well- 
established doctrine of the localisation of brain function, the 
