THE STANDPOINT OF BIOLOGISTS. 21 



Darwin's Law of Selection. 



The law of selection brought forward by Darwin 

 and Wallace may be stated as follows : No two off- 

 spring of the same parents are quite similar to 

 each other, indeed they often vary to a consider- 

 able extent. Under the conditions in which they 

 live, some of these offspring will have an advantage 

 over the rest, dependent upon an inborn peculiarity 

 Inasmuch, therefore, as more progeny are produced 

 than can ever survive, those most fitted to these sur- 

 roundings will have the better chance of living. 

 These will, in larger numbers, perpetuate the race 

 and transmit their inborn qualities to the race, thus 

 gradually eliminating the less suitable ones. 



Keeping to the case of the giraffe, Darwin and 

 Wallace would explain the length of the neck 

 somewhat as follows : With Lamarck they believe 

 that the ancestor was short-necked, but the subse- 

 quent elongation they would explain in quite another 

 way. They would take for granted that there are 

 times when grass and foliage are scarce, that short- 

 necked animals would soon exhaust the herbage and 

 shrubs, but that the taller shrubs and trees would afford 

 subsistence to animals with a higher reach. Amongst 

 the ancestral giraffes those born with the longest 

 necks would at such times have an advantage ovei 

 the rest, who in large numbers would die out. The 



