496 



Mr. J. Wood on Variations in Human Myology. [June 18, 



Fig. 5 

 (Subject No. 10). 



In the right arm of the male (No. 10) (noted in column 15 in the Table) 

 was found a brachio-radialis as a detached muscle (fig. 5, a) of considerable 

 size, arising separately from the upper part of the outer condyloid ridge of 

 the humerus and intermuscular septum, just below the 

 deltoid {d) and above the supinator longus (c). Passing 

 as a flat muscular band downwards, forwards, and in- 

 wards, outside the biceps {b), it was inserted by a flat 

 aponeurotic tendon into the oblique line of the radiuSy 

 close below the bicipital tuberosity, and between the in- 

 sertions of the supinator brevis (e) and pronator radii 

 teres (/). Although quite detached from other muscles, 

 and inserted into the radius below the biceps, the homo- 

 logical relation of this muscle, in the situation of its 

 origin from the humerus, to the fourth head of the bi- 

 ceps just alluded to (recorded in the author's paper of 

 1864), is clearly apparent; and it holds the same rela- 

 tion to that external humeral head of the biceps as the 

 detached hrachio-fascialis, described in the author's 

 papers of 1864, 1865, and 1866, does to the internal 

 humeral head of the same muscle. Meckel, quoting 

 Pietsch (Journal de Roux, t. xxxi. p. 245), mentions an 

 instance in which three humeral slips, one from the 

 outside of the humerus (homologous with the foregoing 

 abnormality), one from the inner side (homologous with 

 the more common third head), and one from the short 

 or coracoid head of the biceps, joined together to form 

 one muscle, which was inserted into the radius by a 

 separate tendon, behind the normal one, upon the bici- 

 pital tuberosity (Muskellehre, S. 504). He also quotes 

 Rudolphi (in Blumenbach's Med. Bibl. Bd. i. S. 176) 

 and Sels (Diss. Anat. Muse. Variet. sistens, 1815, 

 p. 12) for an instance in which a muscular bundle of the 

 size of a finger passed from the outer head of the 

 biceps to be inserted separately into the radius. The 

 more perfectly detached form of this abnormality is also alluded to by 

 Theile (in Soemmerring's Encyclop. Anatomique, Jourdan's Trans. 1843, 

 p. 217), by R. Wagner (in Heusinger's Zeitschrift, Heft iii. Bd. iii. S. 345), 

 and by Hyrtl (Lehrbuch). A case very similar to the present has been 

 described by W. Gruber (in Miiller's Archiv, 1848, S. 428) as a variety of 

 the brachialis antieus, in the right arm of a very muscular male, in whose 

 left arm was found the more common form of the third head of the biceps. 

 It arose from the humerus, close to the outer condyloid ridge, as a thick 

 muscle, and was inserted by a separate tendon into the radial tuberosity 

 just below the biceps, giving off a slip of tendon to the aponeurosis of the 

 forearm. 



