ANIMAL COLOURING 
227 
he observed, the colour was transferred from the food 
to the feeder, also suggests the existence of some 
simple and natural relation between the tints in the 
skin, or hair, and external conditions of food and 
temperature, to account for the strange changes of 
colour to suit outside conditions in animals exposed to 
the rigours of a northern winter. The mountain hare 
of Ireland does not always change its colour to white 
in winter, though in the colder climate of Scotland 
and Norway the change is the rule. So the Arctic 
fox seems always to be “ bleached ” in the extreme 
north, though often retaining its darker dress through- 
out the year when further south. Yet exactly the 
same effects are found in connection with want of 
food as with want of warmth. The rats in a large 
iron ship which was recently wrecked off the coast of 
Northumberland , 1 and remained stranded for many 
weeks without connection with the shore, turned quite 
white — a change due apparently to starvation. 
In strong contrast with the modifications of the 
part played by evolution in animal colouring, sug- 
gested by Dr. Eisig, is the alternative which Mr. 
Stoltzmann proposes to the theory of sexual selection. 
It is not a change which will flatter the masculine 
imagination. Contrasted with the view which ac- 
counted for the predominance of male strength, and 
in some cases of masculine beauty, over the weaker 
1 Near Blyth. When some shipwrights visited the vessel to 
remove rigging and fittings, the starving rats swarmed round them, 
and ate the food which they had brought for their dinners. 
