258 TRANSACTIONS OF THE [may 13, 
arising from the capsule of the shoulder joint and attached to 
the deep surface of the Pectoralis major tendon (Capsulo-pec- 
toral variety of Gleno-ulnar head). About 4 cm. above the 
elbow joint a slip separates from the inner border and deep sur- 
face of the main muscle, and, becoming tendinous, passes down- 
ward and inward to the anterior border of the ulna, just below 
the coracoid insertion of the Brachialis anticus. (Persistent dis- 
tal portion ef Gleno-ulnar division). 
II. Coracoid Heads. 
A broad muscle, arising with the Coraco-brachialis from the 
‘ccoracoid process, divides at the level of the lower Pectoralis 
margin into: (a) The usual short or coracoid head, which passes 
down and out and joins the outer head a little above the middle 
‘of the arm (Coraco-radial division). (b). An internal muscle, 
‘completely free from Coraco-brachialis, which immediately sub- 
-divides into two equal portions. Of these the posterior and in- 
‘ternal muscle descends vertically over the Coraco-brachialis in- 
sertion, and terminates at the junction of middle and lower one- 
third of the arm in a strong tendon, which passes down, at first 
free and subsequently fused with Struther’s ligament, to the in- 
ternal epicondyle. (Coraco-epitrochlear variety of Gleno-ulnar 
head. 
The anterior muscle, lying upon the Brachialis anticus and the 
internal intermuscular septum, remains completely free from 
surrounding structures and terminates in a strong tendon which 
passes over the elbow joint and is inserted into the coronoid 
process of the ulna, just internal to the Brachialis anticus inser- 
tion. (Typical Coraco-ulnar head of muscle.) 
This case is especially important, as it presents not only the 
“more common proximal vestiges of the obsolete ulnar divisions, 
but also exhibits perfectly the rare distal or insertion portions, 
-in their complete form, attached to the ulna. 
The separation of the Biceps insertion from the ulna and the 
assignment of the muscle, as a supinator, to the radius, would 
lead us to expect this disproportion, as regards frequency of oc- 
currence, between reversions of the complete distal and proxi- 
mal segments of the lost ulnar division. The distal or inser- 
tion portion of the ulnar division was the first to disappear at 
the insertion into the ulna, and consequently reverts in a very 
much smaller percentage in its complete form than the proxi- 
mal or origin portion, whose existence has, so to speak, been 
prolonged by the opportunity of uniting with the radial division. 
The above instance exhibits these features of the muscle-plan 
perfectly, and the preparation has been added to the Variation- 
series of the Morphological Museum of Columbia College. 
