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MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



perforations. There was usually uo great difficulty in doing this, as the margins of the former 

 were smooth and bounded a fenestration, regular or subregular in shape often oval, while the 



irregular and fractured character of the margins of the latter 

 was readily discernible. But it is probable that bones once 

 perforated naturally were afterwards perforated post-mortem 

 by fractures which included the natural fenestrations, or that 

 the smooth edges of natural openings may have been abraded 

 so as to give them the appearance of accidental openings; 

 such cases would be excluded from the list. 



Not only is the perforation more common in this than in 

 any other race, but, as far as our observations among the va- 

 rious series iii the Army Medical Museum teach us, the num- 

 ber of large perforations is proportionally greater. Such, at 

 least, was the impression gained (luring the examination ; but 

 we did not determine this by actual measurement. Fig. 46 

 represents, natural size, the lower extremity of a left humerus 

 of an ancient Saladoaii in the I lememvay collection. It exhib- 

 its an olecranon perforation 11 milimeters in length by 7 in 

 width. 



The following table of five series in the Army Medical 

 Museum shows that the perforation is more commonly found 

 on the left side than on the right; yet even in this particular 

 the Saladoans differ much from the rest of the races. While 

 with them, as with others, the perforation is more commonly 

 found on the right side, the difference between the two sides 

 is not so great. This is shown in the last column of the table. 



The subject of the olecranon perforation has been so ex- 

 tensively discussed* that we deem it well to do little more 

 than give the results of our studies of the Hemenway series 

 and other series in the Army Medical Museum, and indicate how our discoveries bear on the whole 

 subject. 



TABLE T. Showing percentages of olecranon perforation, on the right and on the left stidt, in differ- 

 ent peoples. 



FIG. 46 Lower end of hnmerus showing large) 

 olecranon perforation. 



We will attempt neither to cite the various theories which have been proposed to explain the 

 nature and origin of the perforation, nor to quote the many arguments advanced to sustain these. 

 theories. We will merely announce that we are among those who believe that the perforation is 

 not congenital but acquired; and that it has no connection with the rank a people may hold in the 

 scale of races, but is the result of some mechanical cause connected with their occupations. We 

 believe, furthermore, that it results from repeated and forcible extension of the forearm, in which 

 the summit of the olecranon process of the ulna impinges against that thin bony partition which 



' For a synopsis of the discussion and a bibliography of 49 titles, see "The Olecranon Perforation," by Dr. D. S. 

 Lamb, in The American Anthropologist for April, 1890. 



