420 The Outline of Science 



of a goat, but there is always a certain resemblance to the human 

 voice in it, especially when the birds are unalarmed, and converse 

 with each other in subdued tones." The Heron is a bird of the 

 woodland, in so far as it is there he makes his heronry. It will 

 frequently be found closely adjacent to a rookery, but the two 

 colonies do not always live at peace, although in a case the writer 

 knows of, quite near London, they have done so for many decades. 

 The Rooks are numerous and aggressive, and though an indi- 

 vidual Rook could not hold its own with a Heron, numbers 

 usually prevail when a battle royal takes place. In habit the 

 Heron is a bird of the brook and river, and there can be little 

 doubt about his favourite diet being of fish. He loves to stand 

 in a clear, shallow stream, apparently motionless, but should an 

 eel creep out, or a bolder trout try to make a passage up-stream, 

 the Heron's keen eye sees it at once and down comes his beak 

 like a sharp spear, the chances being that the next experience 

 of the fish is that of being borne through the air, to be eventually 

 swallowed and either wholly or partly digested. In the latter 

 case, the process is stopped in order that the young may receive 

 the food in a softened condition. 



The Green Woodpecker is a common British species, whose 

 bright plumage is less conspicuous among the trees than might 

 be thought, but whose presence is often betrayed by the loud 

 cry like a burst of demoniac laughter -or by the strong "tap, 

 tap, tap" of its beak as it sounds the tree-trunks for rotten por- 

 tions where insects may be found. The woodpecker's strong 

 beak, adapted to its mode of feeding, is well suited also for the 

 work of excavating a nesting hole, and a deep cavity with a 

 small horizontal opening at the top is hollowed out. 



The Waterhen and the Coot 



The Waterhen looks black at a distance, but on closer obser- 

 vation discloses many charming shades of colour. It is a bird 

 that seems to thrive and increase in numbers more than its com- 



