THE SIGNIFICANCE OF HUMAN ANOMALIES. 725 



there are more, and, when this occurs, the extra ribs are carried by 

 the neck (cervical) or loin (lumbar) vertebrae. I have specimens in 

 my collection of both varieties, cervical and lumbar (see Fig. 2, C). 

 These supernumerary ribs do not occur very frequently ; still, every 

 anatomist has observed them. Their occurrence becomes more intel- 

 lio-ible when we know that in crocodiles, birds, and the three-toed 

 sloth, neck or cervical ribs exist normally ; that in crocodiles, alligators, 

 and some other animals, loin or lumbar ribs are never absent ; and that 

 in man traces of them exist in the muscles of the abdomen. In the 

 human embryo, in an early stage, a rib is always seen connected with 

 the seventh neck-vertebra, but before the fifth year of life it becomes 

 blended with the ordinary transverse process (Fig. 2, T) ; occasionally, 

 however, this rudiment goes on developing, till it becomes a more or 

 less perfect cervical rib (see Fig. 2, C). 



SuPRA-coNDYLOiD PROCESS. — It is not uncommon to find, in the 

 humerus or arm-bone of man, a hook-like process on the inner side of 

 the lower end, having a downward direction; this, with a band of liga- 

 ment which connects its tip with the humerus lower down, forms a 

 foramen or opening through which pass the great artery and nerve of 

 the arm (see Fig. 3, A, B). This foramen is found in about three per 



Fig. 3.— a, the snpracoadyloid process of tlie human Fig. 4.— Bones of Fore-limb of Cat. S, 

 humerus ; B, the lio-ament which completes the fora- the supracondyloid foramen, with ves- 

 men. (After Struthers.) sel and nerve passing through. (After 



Struthers.) 



cent of recent skeletons, but much more commonly in the skeletons of 

 ancient races. In very many bodies a trace of this foramen is seen, 

 represented by a very small bony prominence, or only by a band of 



