n 



XX. ANIMALS IN THE DARK 



WHEN a thick fog descends on London, it often 

 stops like a blanket just above the summit of the 

 ordinary buildings, though the tops of the towers and 

 great hotels are covered with darkness. All the pigeons 

 and sea-gulls, which are sitting on the towers and 

 pediments, or soaring over the river, hasten to descend 

 into the light ; and while the former settle on the lower 

 ledges and cornices, the latter skim over the Thames 

 below the fog-belt, where they can see the world around 

 them. 



Thick fog bewilders all animals ; and in real darkness 

 that is, in total absence of light they are no more able 

 to see than man. In the ' Mammoth Caves ; they lost 

 their eyes, as they do in the deep seas ; and even in the 

 catacombs below Paris there are signs that some such 

 change would in time take place. But the power of 

 sight in what we term ' the dark ' is the rule, and not 

 the exception, among the great majority of animals. 

 The list of those which are either unable to find their 



'45 10 



