94 ANIMAL LIFE UNDER WATER 



the book above the level of the head, with the 

 arms extended at an angle of forty-five degrees 

 to the body, then twist the book until the photo- 

 graph is in a horizontal position. 



The surface of water beyond the arc of the 

 "window" is dark because of insufficient 

 photographic exposure. It is impossible to 

 get a correct photographic exposure for the 

 " window " and for the area of total reflection 

 on the same plate in consequence of the bright 

 light through the " window." 



I have taken the heron as an example because 

 of its bold plumage marks. 



Waders that show less contrast are equally 

 well concealed with rushes and reeds behind them. 



Colour is also of value to the wader. In 1917 

 I watched flamingoes in the water at the mouth 

 of the Wadi Guzzee in Palestine, and it struck 

 me then how well the crimson of their plumage 

 would blend with the ruddy sky which rimmed 

 the "window " of an Eastern fish. 



To return to the heron. If the bird is really 

 concealed from the fish, as I have described, it 

 should be possible for it to stand in clear water 

 and catch as many fish as it requires. Provided 

 that the fish are there and that the water is suit- 



