2 oo ANIMAL LIFE 



as we review each group in its response to the welfare 

 of the race. 



The most majestic of these responses is that of 



Fn;. 35. — Transformation of a groundling Sea-worm (Nereis), a, into a 

 migrant of pelagic waters, 13, The eyes are enlarged, the paddles more 

 complex and effective. — (After Quatrefages.) 



migration. Under the stress of a cause not their 

 own, birds and fish assume a new aspect and travel 

 with their mates to far-off, traditional nesting-places. 

 On this journey they behave as creatures possessed. 



