24 
BIRD-LIFE. 
rapid movement. When moving quickly all birds throw 
the body very much forward. At each step the bird 
raises the thigh and tarsus, both up and forwards, it then 
stretches out the leg, touching the earth about the midst 
of this stretching motion. With their advance the body 
is next raised, and, through this movement being per¬ 
formed with a jerk, is thrown forward, by which means 
the hinder portion of the foot leaves the ground, which 
latter remains, for a moment only, in contact with the 
points of the toes. The result of this is, that with every 
foot-print of a bird on soft ground we find an exact 
impression of the ends of the toes. Now, should the 
bird’s carriage be very erect, its gait is rendered more 
difficult by reason of the leg bending less at the knee and 
the ankle when stepping out, and thus being more 
extended while in motion; if the carriage be nearly 
horizontal the whole body is thrown over towards the 
side opposite the leg which is stepping forward. Birds 
standing erect, like the Divers, must do so with their 
legs far apart, if they would keep their bodies properly 
balanced. Hopping-birds move whilst bending both 
knees and ankles, and slightly raising the wings, then 
suddenly drawing in and stretching out the legs; thus 
springing both upwards and forwards. Birds that hop on 
the ground stand erect; while those which hop on trees 
hold themselves horizontally, with their legs much bent. 
When a bird wants to run faster than usual it makes use 
of the wings as accessories to the legs, and in such cases 
its action consists of a series of springing steps, like 
those of the Ostrich running apace, or a sort of half 
running, half flying pace, like a harried barn-door Fowl. 
Some birds run along on the surface of the water, but 
this must, at least, in the case of very long-toed birds, be 
