I'M) l!ii:i)s. 



;ill tlic lum<li-('(ls of dittrriiii:' ti-ihos'of the fciitlicrcd nice 

 we liiid IK) such straiiirt' and alx-n-anl toi'ins as wc have 

 among tlic mannnals in the winded Uals or tlic tinni-d 

 \\'haU's, It is ti'nc that all hirds do not fly. hut they do 

 all pofcisejss wiiiirs oC some sort. Ihouiih they may use them 

 oidy as Hn.s, :is do the l\'njiiiius, oi- as aids in running-, as 

 do the Ostiichos. 



Intense activity characterizes all ihe functions of the 

 body as well as ni'eat ctHciency. Nowhere (dse do w c 

 find so com[)letc a i('sj)iratory system, for, besides the 

 j)iM'itication of Ihe l)lood in the Innifs, the capillaries meet 

 the air in sacs, which arc tlistrihnted in \arions i)arts of 

 the l)odv. TIh'sc arc chieflv to make the hodv lijrht hut 

 they also assist the luniis in their woi'l<. The hones are 

 all very compact and liini : those of the neck move vei'v 

 ficelv allowini:' motion in all <lii'ections, \vhile those of the 

 back, to which the winu's and le<:"s are attached are fast- 

 ened toirether so closel\ as to be almost immovable. The 

 one main purpose and aim in the plan of .strnctiu'e seems 

 to be titness for tliirht. The tirm museles. the (piickly 

 bcatiiiL'" heart, the liiiht, compaeth' built bod\ . the eneruv 

 of all the parts, unite in the accomplishment of this end 

 and so eirectually do they fullill their mission that the 

 speed and jxiwer of lliiiht in man\ hirds are vejy great. 

 The Hawks and their allies can lly from eighty to oik; 

 hundred miles an hour, tlieir swoop being nuieh more 

 rapid, and many of oui' smaller birds, as the SwalloAvs and 

 AVarblers, i\y almost or (piite as rapidly and not only is 

 their tbu'ht so swift, but thev ean keel) on the win<i: tor 

 hours, or even days, with little or no rest. The eyes of 

 an animal moving so constanth' and so ra])idly nmst have 

 a different structure from that of man or othei' animals 

 that move more slowly or it could not accomplish its pur- 

 j)ose, aeeordingly we tind all the i)arts (jf a bird's eye 

 freely movable, and controlled by muscles. The eye of 

 tlie Hawk, which lies flattened and far sighted as the bird 

 sails slowly along the up})er air, as soon as any prey is 



