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^j achdruck verboten. 



Variations in tlie Teres Minor muscle. 



By David Waterston, M. D., Edinburgh, Lecturer on Anatomy, 

 Edinburgh University. 



With one Figure. 



Some specimens showing unusual variations in the Teres minor 

 muscle, associated with an alteration in the fascia infraspinata have 

 occurred recently in the dissecting rooms of the University of Edin- 

 burgh, and as they appear to throw some light upon the morphology 

 of the musculature and fascia of the infraspioous region they deserve 

 to be placed on record. 



The notes of the first specimen are as follows: 



The subject was a male, with well developed muscles. In the 

 right arm, the origin of the teres minor was much more extensive 

 than usual. The muscle was not confined to the axillary border of 

 the scapula, but its inner margin was prolonged inwards over the 

 infraspinatus muscle, taking the place of the fascia infraspinata. By 

 means of fleshy fibres, the muscle gained an attachment to the lower 

 margin of the spine of the scapula and to the vertebral border of 

 that bone. Towards the lower angle of the infraspinous fossa, the 

 muscular tissue was replaced by fibrous tissue, which formed an 

 aponeurotic origin for the lower fibres of the muscle. On reflecting 

 this thin sheet of muscle, the infraspinatus muscle was found lying 

 subjacent to it, separated from it by a thin sheet of fascia. The 

 nerve supply of this enlarged Teres minor came from the circumflex 

 nerve as usual. 



Notes were also made of two other specimens, in which the same 

 condition was found, but in them the sheet covering the infraspinatus 

 was not so uniformly muscular, but consisted to a greater extent in 

 its inner part of fibrous tissue. In these two specimens the appearances 

 suggested that the inner margin of the teres minor had invaded the 

 fascia infraspinata and replaced it in the outer part. 



The fascia infraspinata is always a particularly strong and dist- 

 inct layer of fascia, and its character suggests the idea that it is the 



