BTBDS. 285 



On each side of the well-known bone which is called the 

 " merry -thought" (furculum), is one of a less symmetrical form, 

 one extremity being thin and Hat, while the other is spread out 

 into a stronger and broader shape. If these bones be examined 

 with reference to their uses in the framework of the bird, we 

 find that the thinner side of the last mentioned is, in fact, one 

 bone,* the broader side another bone,t constituting the great 

 support of the shoulder ; and that the " merry -thought" is com- 

 posed of two joined together,^: forming a figure like that of 

 the letter V, the whole being so many buttresses to keep the 

 shoulder joint firm and steady. 



It may not be uninteresting to contrast the skeleton of the 

 strich (Fig. 237) with that of the Vulture (Fig. 240), and to 



Fig. 240.— Skeleton of thb Vvlturk.§ 



observe the difference they exhibit in the bones of the wing, 

 and several other particulars. 



The bones of birds are not, however, remarkable only for 

 their form or arrangement, but also for a peculiarity of struc- 



• The Scapula. f The Coracoid. J The Clavicles. 



§ re cen-ical vertebne : vs. sacral vertebrse ; vg, caudal vertebrae ; st, sterntmi ; 

 W, clavicles, A, humerus; o, bones of the fore-arm ; w, carpus; ph, phalacgca; /, femur; 

 (, tibia; ta, tarsus. 



