BIRDS. 131 



(Icscricd tar hclow it, has every muscle reach' t'ur action 

 and. as the bird sweeps down with the speed of wind, not 

 oidy do the winirs perform their i)art, not only do the talons 

 and beak i)rei)are for action, but the eye is all the time 

 being draAvn out round and full and when the earth is 

 reached it is as keenly near sighted as it was far sighted 

 an instant before and if the bird chance to turn toward 

 the sun the third eyelid, the silvery nictitathig mem- 

 brane springs over the eye and shields it from harm. 



But, hoAvever interesting the structure and action of the 

 various parts of a bird's body, an extended consideration 

 of them is foreign to our [)resent purpose and so we pass 

 on to notice veiy In'ietly tlie relations of birds to other 

 animals. In their mode of reproduction and in the 

 structure of some of the parts of the body birds have 

 some affinity with the reptiles, but in other respects there 

 is a irreater resemldance to the manmials. Between these 

 two classes, though not in all respects strictly intermedi- 

 ate, the birds are placed. There is no necessity for giv- 

 hig in this place a detailed classification and we will pass 

 this part of the subject by simply stating that many natu- 

 ralists arrange the birds in two groups, one embracing 

 those that hatch the young in a weak condition and so are 

 obliged to feed and care for them for some time, as is the 

 case with the Kobin and other of om- conmion song birds ; 

 the other group eml)races such birds as the Partridge and 

 our common fowls, whose young are a])le as soon as hatched 

 to run about and care to some extent for themselves. 



Besides this general division some more specitic arrang- 

 ment is adopted. That most used by naturalists com- 

 prises seven orders which will be taken u[) in turn, 

 though little need be said of most of them as they are not 

 of s})ecial interest to the agricnltuiist and one order that 

 of the Cursores or runners Avhich is composed of I)irds 

 such as the Ostrich and Cassowary will be omitted en- 

 tirely. At this time oidy those si)ecies which are fouu<l 

 within the limits of Vermont will l)e noticed. 



