356 Appendix B 



too, congenital variations would follow in the wake of accommo- 

 dations, due to exercise, in the individual. 



'' The other examples which I take will show how parental 

 affection gave a new importance to this principle. 



" First I will consider the process by which birds became 

 bipeds, using their hind-limbs only for walking, and devoting 

 their fore-limbs to flight. Let us assume that they first learned 

 to fly by flapping along the surface of water, flying with their 

 wings and paddling with their feet. When they took to hving 

 on land, not only would flight, being unaided by the feet, be 

 more difficult, but they must become bipeds else their wing 

 feathers will suffer. Now walking on the hind legs is by no 

 means an easy feat for a bird till he has been specially adapted 

 for it. What a clumsy creature a penguin is on land ! How 

 often he trips and tumbles ! But power of running is often 

 indispensable to a bird ; many birds in the present day rise 

 from the ground with difficulty, and without ample space cannot 

 rise at all, so that unless they were good on their legs, they 

 would be as helpless as a Boer without his horse. Much less 

 could the primitive bird when he emerged on to the land do 

 without speed of foot, unless like the penguins he was lucky 

 enough to have no land enemies to pursue him. He must, 

 therefore, practise and improve at running, and the result might 

 well be that a small peculiarity of structure would be raised to 

 importance ; having a slight gift for running he would become 

 through much practice an adept according to the primitive avian 

 standard. And now comes in the factor of parental training, 

 for we must imagine that having advanced so far in strength, 

 skill, and vitality as to be able to fly, he will not leave his young 

 to fend entirely for themselves. They will have the path of life 

 marked out for them by their parents. They must not return 

 to an aquatic existence, only occasionally landing for rest, at 

 safe spots, but they must be able to stand, walk, run in biped 

 fashion. In fact individuals dictate to their offspring what 

 mode of life they shall follow, choose the environment that is 

 to act upon them, and, each generation making a similar choice, 

 development proceeds cumulatively along certain lines ; only 



