THE STEENUM IN BIEDS. 



281 



in the posterior moiety of the sternum when ossification 

 takes place, and give rise to as many holes, or deep notches, 

 separating slender processes in the dry skeleton. All these 

 correspond with so many divisions of the xiphoid process 

 of the sternum in Mammalia, and hence are called middle, 



Fig. 81.— Front and side views of tiie sternum of a Fowl, r., rostrum, 

 or manubrium ; c. p., costal process ; pi o., pleurosteon (the line from 

 the letter goes to the point of junction between the pleurosteon and 

 the metosteon) ; m. x., the middle xiphoid process; ca., the carina or 

 keel. 



internal, and external xiphoid processes. Sometimes, a median 

 process, rostrum or manubrium (r.. Fig. 81), is developed from 

 the anterior angle of the stei-num, and its antero -lateral 

 angles are frequently produced into costal processes {c.p.. 

 Fig. 81), which may hear the articular surfaces for more or 



