34 CONTROLLED NATURAL SELECTION 



without doubt, that the upper surfaces are 

 conspicuous in Nature and the under ones 

 inconspicuous. 



It is probably an advantage for Admiral 

 butterflies to be able to see other Admiral 

 butterflies on flowers, from a distance ; and 

 thus to find good food and mates, &c. 



The Tadpole (Rana Temporaries), when 

 very young, is coloured uniformly black. At 

 this stage, they keep together in colonies, 

 forming black wriggling masses, as noticeable 

 from under water as from above, and make, 

 when disturbed, no effort at concealment. 



It is noteworthy that the black of the young 

 tadpole, like the black of the frog's ovum, 

 may be for the purpose of absorbing the sun's 

 heat. 



Experiments have shown that young tad- 

 poles are unpalatable to both birds and fish ; 

 it seems, therefore, that they can with safety 

 render themselves conspicuous, and utilise 

 the beneficial heat-absorbing property of 

 blackness. 



Sufficient examples, and they could be 

 multiplied almost indefinitely, have now been 

 given, to show that many animals are con- 

 spicuous in Nature and make no attempt to 

 conceal themselves. 



