HOW WE DEFEND OURSELVES FROM OUR FOES 93 



HOW WE DEFEND OUESELVES FKOM OUR FOES 



B? Pbofessob FRASBR HARRIS, D.Sc. 



DALHOOSIB UNIVERSITY, HALIFAX, N. S. 



IN a certain sense even now in the midst of his civilized communities, 

 mankind is waging ceaseless warfare against a number of hostile 

 conditions, both animate and inanimate. Serious as this may be now, 

 it must have been much more acute in the earlier times of the race. 



Man had to defend himself, as best he could, from the great cosmic 

 exhibitions of energy — the extremes of heat and cold, the tempest, the 

 lightning, the avalanche, the earthquake and the tidal wave. Primitive 

 man, we are assured, must have lived in the midst of alarms of all sorts 

 and in the constant dread of attacks by fierce animals far more powerful 

 than himself. Undoubtedly he sought shelter from wind, rain, Bnow 

 and frost in those caverns in which his skeleton and the bones of the 

 animals he slew for food and fur are yet to be found. 



In many parts of the world he built his wooden hut on piles out 

 from the shore of some lake, so that he had his food supply in the fish 

 under the floor, and was also more secure against the wild animals 

 when his dwelling had to be defended on one side instead of on four. 



The latent powers of his nervous system permitted him to develop 

 that speed of running in flight whereby he saved himself from the 

 avalanche, the tidal wave or the beasts of the field. Not alone was 

 speed necessary, but also rapidity of response on the part of his nervous 

 system in order to take warning from the impending danger : that man 

 lived longest who most rapidly reacted to the danger signal, stepped 

 most agilely out of the way of the rolling boulder, skipped most briskly 

 aside from the infuriated lion or bear. 



Of course, as we know, he early devised his weapons of offence and 

 fired his flint-tipped arrows at the animals threatening his life or 

 destined to be his store of food for a long time to come. That man 

 throve best who most accurately threw his stone or javelin, so that 

 quickness of response (short "reaction-time") and accuracy of aim — 

 both powers of the nervous system — were early in the history of our 

 race the means of escape from enemies, or the mode of procuring a 

 sufficiency of food. 



The first human line of defence is then nervous or mental; our 

 ancestors established themselves on the earth by means of such powers 

 of the nervous system as speed, accuracy and coordination of move- 



