148 R. Anderson, 



In its conrse from without inwards, the muscle is arched, and 

 helps to enclose an elliptical space situated above the clavicle. 

 Through this space the descending branches of the cervical plexus pass. 

 A considerable branch from the inner cord turns up over the supra- 

 clavicular muscle and joins the second nerve ; from the loop so formed 

 the superficial cervical takes origin. 



The supraclavicularis receives a nerve from the descending branch 

 of Hypoglossus. 



The inner attachment of this specimen differs from that described 

 by Professor Gruber in the fact that the inner attached lies between 

 two parts of the sternomastoid , whilst that of Prof. Gruber lies 

 behind this muscle. The second example met with by me received 

 its nervous supply from the descending branch of Hypoglossus and 

 corresponded exactly to the description given by W. Gruber. 



The supraclavicularis proprium has been compared to the supra- 

 clavicular bands that run from the inner to the outer end of the 

 clavicle, forming V7ith the latter an eUiptical space, through which the 

 descending branches of the cervical nerves pass, and receiving the 

 attachments of the trapezius and sternomastoid (Gruber). The deeper 

 Position of these muscles seems to show that, they are slips perfectly 

 independent of the trapezius and sternocleidomastoid, which the 

 supraclavicular bands are not. The nervous supply points in the 

 same direction, and, on the whole, the supraclavicular muscles seem 

 to be varieties of the same transverse muscular bands. The names 

 retroclavicular , sterno - or costo - scapular indicate their attachments. 

 The example I have given of the stemoscapularis is important, as it 

 Shows that an original high attachment of this muscle existed 

 and the condition is just such as we should expect to have, if 

 a portion of the omohyoid lost its attachment to the hyoid bone above^ 

 but maintained its attachment to the sternohyoid or sternothyroid. The 

 muscle formed by the conjoined pieces of the sternohyoid (sternothyroid) 

 and omohyoid would in contracting be carried down to the level of 

 the clavicle and might bring down a cervical nerve-loop. The same 

 explanation probably holds with reference to the costoscapular above 

 mentioned. The stage we can see for ourselves in certain varieties of 

 the omohyoid ; let us suppose the case of a posterior belly of the 



