i;o THE STRUCTURE AND LIFE OF BIRDS CHAP. 



with the relationship between families within the same 

 class, but with the relationship between two classes. 

 In the crocodile the muscle in question appears either 

 not to connect with the toe-flexor muscles or else to 

 be altogether functionlcss, tor when I have bent the 

 ankle-joint o( a young American alligator, most pro- 

 bably resembling a crocodile in this point of anatomy, 

 no effect at all has been produced upon the toes. 



The habit o( standing on one leg is common to 

 many birds. The Heron is well known for it. 



'*Ni v L;h upon that hour 

 When the lone hern forgets his melancholy, 

 Lets down his other leg ami, stretching, dreams 

 Of goodly supper in the distant pool." 



Flamingoes, Storks, and Cranes can frequently be 

 seen in this posture at the Zoological Gardens. 



It is said to be a restful one, and it must have 

 merits or they would not adopt it. Hut if the leg be 

 watched it will be seen to be perpetually swaying to 

 and fro. In fact the balance is only maintained by 

 the help o( perpetual small muscular adjustments, of 

 which, no doubt, the bird is capable while asleep, 

 some lower part oi~ the brain working when the cere- 

 bral hemispheres, the seat of conscious life, arc at 

 rest. 



Su imming. 



People maintain that they have seen from a boat a 

 Shag " flying under water," swimming, that is, by 

 means o{ his wings. Among the diving birds at the 

 Zoological Gardens there is frequently a Shag, and as 



