328 



Further, iu many cases while there was a distinct articulation 

 with the side of the raetasternum the greater part of the cartilaginous 

 extremity of the rib was found in front of the metasternum the arti- 

 culation with the lateral facets being effected by a small dorsal pro- 

 jection. The articulation of the 7th rib with the side of the meta- 

 sternum was as a rule most typical in those cases where 8 sternal ribs 

 were present. 



Two of the cases present variations representing an exaggerated 

 degenerative condition and these may be described in greater detail. 



In the first case the 6th costal cartilages articulated above with 

 the lower end of the mesosternum and in front with one another. 

 The 7th cartilages articulated with the lower borders of the 6th car- 

 tilages and by their extremities with one another. The metasternum 

 was not continuous with the mesosternum but was attached by liga- 

 ments to the dorsal aspect of the 7th cartilages. 



In the second case — that of a badly developed girl of 18 — the 

 mesosternum terminated at the level of insertion of the 5th ribs. The 

 extremities of the 6th and 7th cartilages on the left side were fused 

 together-those on the right side were closely united by fibrous tissue. 

 The two bars formed in this way — one fibrous, the other cartilaginous — 

 articulated with the mesosternum above and with one another in front. 

 The metasternum in this case also, failed to join the mesosternum and 

 was attached by ligamentous tissue to the dorsal aspect of the se- 

 condary bars formed by the ends of the 6th and 7th ribs. 



These cases may be compared with one reported by Dwight (7) 

 where the condition is thus described : "The body (of the sternum) as 

 seen from the front, ends at the level of the insertion of the 4th pair 

 of costal cartilages. The 5th pair are attached to its lower end. The 

 5th, 6th and 7th pairs of cartilages meet one another and their fellows 

 of the opposite side forming a cartilaginous continuation of the sternum. 

 Seen from behind the body appears a little longer, — a thin layer of 

 ossification extending down between the 5th cartilages. The ensiform 

 cartilage was almost wholly cut away. What little is left contains no 

 bone and appears to spring from the deep surface of the united costal 

 cartilages." 



While comparatively little attention has been given to the mode 

 of articulation of the 7th rib in this relation yet in connection with 

 other work on the anatomy of the sternum several observations have 

 been made which are of interest. In a few of the textbooks mention 

 is made of the facts that the metasternum generally lies in a plane 

 posterior to the anterior surface of the sternum and that the 7th ribs 



