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causes. Many of the cases of altered attachments are due to subsequent 

 alterations of normally developed muscle germs, and almost any 

 diseased joint will furnish us with illustrations of some of these : for 

 instance, many of the cases in which the biceps tendon is connected to 

 the intertubercular sulcus of the humerus, in place of being attached 

 to the glenoid ligament depend upon chronic rheumatic disease, and 

 muscles may be fastened to anomalous sites on bones as a result of 

 local inflammation, of wounds, of fractures or dislocations, or from dis- 

 ease. 



Of the first class of anomalies, or those muscles not forming parts of 

 the typical human frame, the following examples have occurred to me 

 within the past session : — 



1 . Two specimens of the rectus thoracicus — one a large and well- 

 marked muscle, the other weak and aponeurotic, and both were un- 

 symmetrical, and on opposite sides. This muscle has recently been 

 carefully illustrated by Professor Turner, of Edinburgh, in the " Journal 

 of Anatomy," No. II., p. 246, pi. xii., fig. 1-6. Of the instances figured 

 by him, fig. 6, the right side resembled the first of these which I 

 have found, and the other resembled the left part of fig. 3. Of the cases 

 published by Turner, five were on the right side, two were on the left, 

 five were mesial or crossing, and nine were symmetrical. All the spe- 

 cimens which I have seen have been eleven, and of these, two were 

 double, eight single, and on the right ; and one single, and on the left. 

 Gruber, in the " Memoires de 1' Academielmperiale de St.Petersbourg," 

 torn. iii. 1860, describes having found it symmetrical thrice, and having 

 seen it single once, on each side. Wood mentions three examples on 

 the right side, one on the left, and one symmetrical instance. Hallett 

 mentions many instances, but gives no numerical account. Prom these 

 forty-two specimens, it will be seen that the symmetrical instances are 

 to the unsymmetrical in the proportion of fifteen to twenty- seven ; and, 

 of the latter, the specimens on the right are to those on the left as seven- 

 teen to five. Turner has supported the opinion first broached by Wilde 

 (" Comment. Acad. Petropol.," vol. xii. 1740, p. 320); and Hallett, 

 that it is connected with the cutaneous system of muscles — a part of 

 the panniculus ; but I think we may see some reasons for holding a 

 different opinion, especially in connexion with its tendinous linese trans- 

 versa, seen by Hallett and Meckel, and with its connexions with the 

 sternomastoids, the rectus and the ribs, it seems, generally, at least, to 

 be a true vertebral, or rib muscle. Besides, I think we may have a dif- 

 ferent opinion, upon theoretical grounds, to be stated hereafter. 



2. The cleido- occipitalis occurred five times during the past year ; 

 one of these was on the right side of the neck of a male subject, and 

 arose from the middle fourth of the clavicle on its upper border, ex- 

 ternal to and separate from the cleidomastoid ; passing upwards, it was 

 crossed by the auricularis magnus nerve ; and higher up, by the occipi- 

 talis minor; and, finally, was inserted into the outer half of the superior 

 transverse occipital line. The sterno and cleido-mastoids were per- 

 fectly separated in this subject, up as far as the point of insertion, the 



