68 



Time does not iillow me to go into the subject of the varieties of wing 

 found among the feathered tribes, and therefore I will only make a few con- 

 cluding I'emarks upon the subject of flight. 



In all birds of long sustained flight the winga are long and pointed, and 

 the primaries are set close together so that no air can escape between them. 



The advantage of a long wing is simply that it is capable of a longer and 

 therefore more powerful stroke than a short wing, and it offers more surface 

 for the support of the air. Types of the long wing are to be found in the Albatros, 

 the Swallow, and among the Hawk tribe. 



Those birds wliich fly fast biit seldom fly far have usually rounded wings 

 and much shorter wings ; the rounded form is given by the first two or three 

 of the primary feathers being shorter than those which follow them ; this is the 

 case amongst the gallinaceous birds, such as the Pheasant, Grouse, Partridge, &c. 



Tliis kind of wing requires very intense action and rapidity of stroke to 

 enable it to sustain the bird, as it cannot be worked to so much mechanical 

 advantage as the long wing, and the quills not being placed so closely together 

 the ail' escapes u^^wards. 



I wiU only add a few words upon the mode of turning of a bird. 



Tliis is iisually effected by the bird depressing the inside wing, so to speak, 

 and elevating the outside, and by so doing throwing the centre of gravity inside 

 or towards tlie direction in which the bird desires to turn, and by this means 

 overcoming the law of motion which \irges it on in a. straight line, and at the 

 same time presenting the wings to the air or wind like a sail and thus being 

 blown round ; this motion may frequently be noticed in the flight of the swallow. 



If a bird merely requires to alter its course a little, the change in direction 

 is effected by simply altering the muscular force on one side of the body or the 

 other just as a man turns in walking ; it is also not at all improbable that the 

 wings assist them in turning, although it is difficult to detect any difference 

 in the sti oke of the two wings. 



And now to conclude, I will just notice the tail-end of our subject. This 

 feature in birds has given rise to a good deal of discussion and difference of 

 opinion ; it used to be and still is very frequently given, as its function that by 

 it the bird steers or turns itself ; that this cannot be its chief use a moment's 

 reflection will prove, for it is set on horizontally and not vertically as a rudder 

 should be. 



This then cannot be its chief function, and its use probably is to balance 

 the bird, and it also is a great assistance in stopping a bird. 



AU hovering birds have fan-like tails, and all long-continued flyers have 

 well developed tails. It is very likely that the tail is a great assistance in 

 turning by enabling a bii-d suddenly to stop, but undoubtedly the great function 

 of the tail is to add to the general stability and balance. 



