156 THE WONDER OF LIFE 



of life — these sublime instances of its power and endurance 

 — which are certainly among the most remarkable products 

 of the globe. 



The recuperative power of races varies within wide limits, 

 and it is often difficult to suggest why one type should have 

 so httle and another so much of it. The story of the tUe- 

 fish {Lofhobatilus chamaileontice'ps) is interesting in this con- 

 nexion. It used to frequent the north-east coast of North 

 America, in water about 50° Fahr., and was much fished 

 between 1879 and 1882. In 1882, however, there was 

 a very hard winter, culminating in a great storm which in 

 one night almost put a full stop to the tile-fish. Over a 

 sea-area of some 5,000 square miles the dead fishes were 

 found on the surface in thousands — suddenly killed ofi 

 by a fall of temperature below the hmit of viabihty. No 

 tile-fish was seen for ten years. But in 1902 the small 

 remnant that must have escaped began to manifest itself, 

 and the recuperation gradually set in. 



Plasticity 

 Change of Habits. — The well-known robber-crab 

 {Birgus latro) is a good instance of adaptabihty to a thor- 

 oughgoing change of habit. Birgus should be a seashore 

 animal, and it has to return to the shore to spawn, illus- 

 trating the rule that the young have to be cradled in the 

 ancestral headquarters, but it has become a terrestrial 

 animal. It goes high up the mountains, and Dr. Andrews 

 has photographed it climbing trees. It simply walks up, 

 chnging by the sharp points of the walking-legs, hardly 

 using the large claws at all. Of the robber-crabs at Christ- 

 mas Island, Dr. Andrews writes that they are easily fright- 



