464 PROGRESS OF SCIENCE IN THE CENTURY. 



'^ In its first origin the nervous system is like an 

 open moor, equally easy and equally difficult of pas- 

 sage in all directions, but the nervous system as we 

 inherit it is a labyrinth of paths." Some of these 

 paths are trodden down in antenatal life, but of 

 many of them we can only say that their making is 

 part of our inheritance. But here, as elsewhere, the 

 question of origins cannot at present be answered 

 with any confidence. 



Animal Behaviour. — Let us take a broad survey 

 of animal behaviour. All around us, except in our 

 cities, there is a busy animal life, swayed by the 

 twin impulses of " Hunger " and " Love." There 

 is eager endeavour after individual well-being, there 

 is not less careful effort which secures the welfare of 

 the young. The former varies from a keen and 

 literal struggle for subsistence to a gay pursuit of 

 aesthetic luxuries ; the latter rises from physiolog- 

 ically necessary life-losing and instinctive parental 

 industry to remarkable heights of what seem to us 

 like deliberate sacrifice and affectionate devotion. 



On the one hand, we see struggle, between mates, 

 between rival suitors, between nearly related fellows, 

 between foes of entirely diverse nature, between the 

 powers of life and the merciless forces of the in- 

 organic world. On the other hand, we see the love 

 of mates, family affection, mutual aid among kin- 

 dred, many quaint partnerships and strange friend- 

 ships and infinite inter-relations implying at least 

 some measure of mutual yielding. 



We watch the wondrous industry of birds and bees 

 who work from the dawn until the dusk brings en- 

 forced rest to their brains, which we know to suffer 

 fatigue as ours do; on the other hand we see the 



