100 LABORATORY MANUAL OF ANTHROPOMETRY 



their extremely long and attenuated forearms, are an exception to the 

 general law, and belong in this respect with the lemurs. 



Caliber indices of radius. 



Gibbon (4) 8.1 



Orang (10) 12.8 



Lemur (5; 13.3 



Melanesians (18) 15.7 



Lower monkeys (20) 16.2 



Burmese (8) 16.3 



Negritoes (6) 17.0 



Gorilla (5) 17.1 



Germans, Baden (25) 18.1 



Japanese (3) 20.2 



The radius of H. neandertalensis contrary to expectation, is less 

 slender than in the lower races of the recent species, the index being 

 about like that of the culture races. 



For the two following data, and for some others, one or more definite 

 planes must be determined in which the bone may be placed and from 

 which it may be viewed. The most obvious of these is the volar plane, 

 or approximately that of the two forearm bones when the arm is stretched 

 out in a supine position, with the palm up, a position which brings the 

 radius and ulna parallel to each othei. This plane is determined by a 

 line and a point. The line, which is the maximum length line of the 

 distal articular surface, extends from the apex of the styloid process to the 

 middle of the concave edge of the incisura for the reception of the ulna. 

 The point, which is placed at the opposite end of the bone, is the center of 

 the depression in the capitellum, the fovea capitelli, the point used in 

 the determination of the physiological length. 



To place a given radius so that its volar plane lies parallel to the 

 surface of the drawing table, that is, in a position for drawing a volar 

 projection, the line and point must be placed at the same distance above 

 the table surface. The dor so-ventral, or sagittal plane, lies at exact right 

 angles to this, and is obtained by first placing the bone in the volar plane 

 and then rotating it about its longitudinal axis 90°. With these planes 

 determined the two following measurements may be easily taken, 

 either upon the bone itself, or upon a dioptograph outline. 



6. Transverse diameter of the Shaft. — This should betaken at the point 

 of the greatest development of the crest, a point indicated not only to the 

 eye, but to the finger, being designated by a certain roughness of edge 

 that corresponds anatomically to the insertion of a specially strong band 

 of fibers forming a part of the interosseous ligament. The diameter 

 lies in the volar plane. 



7. Sagittal diameter of the Shaft. — This must be at the same level as 

 the last, but in the sagittal plane, 90° from the last. 



8 Diavhvseal index (7 • 6) = Sagittal diam et er (7) XJ00 



transverse diameter (b) 



