278 BUT HOW TO ACCOITNT FOR HIS OEIGIX. 



should liave come to pass in a more gradual 

 manner — by steps, as it were. 



Suppose then the case of a bear [or any 

 other large land animal, existing or extinct) 

 living on the borders of the then existing 

 Polar sea. We can easily fancy that in the 

 struggle for existence perpetually going on, 

 this bear — or whatever he was — may have 

 been compelled to take to the sea shore and 

 prey upon shell-fish amongst other things. 

 At first he would only go into shallow water, 

 but he would become emboldened, by success 

 and habit, to go deeper and deeper ; even in 

 the lifetime of one individual this would 

 happen, and he would acquire the habit of 

 digging shells up with his feet or his teeth — 

 at first probably with his feet, but latterly, 

 when he came to picking shells in a foot or 

 two of water, he would require to see what he 

 was about, and he would use his teeth. Na- 

 tural selection would now come into play, and 

 as those animals which had the best and 

 longest teeth would succeed best, so they 

 would have the best chance of transmittinsr 

 these peculiarities to their descendants. The 

 tusks of the walrus are not, as I mentioned 

 before, a pair of extra teeth, but merely an 



