Knott — On AhnormaUties in Suman Myology. 407 



LXIII, AByon.TVf ATJTiES n? HiTMAy Myology. By J.F. Kkott, F.E.C.S.I. 



[Read, April 11, 1881.] 



The follomng is an imperfect list of the muscular anomalies which 

 hare come under my notice during the four winters which I have 

 occupied the office of Demonstrator of Anatomy in the School of the 

 Eoyal College of Surgeons. During that time I have paid particular 

 attention to some of those which struck me in the commencement as 

 being specially important or interesting, and which attracted my atten- 

 tion sufficiently to induce me to tabulate the frecjuency of their occur- 

 rence. As I had not the advantage of any co-operation in the research, 

 a very large proportion of the anomalies which might easily have been 

 preserved were necessarily lost, from the fact that it was impossible for 

 me to distribute my attention over the dissection of so large a number 

 of subjects as were always passing through the room. My statistics 

 are, accordingly, in many instances, very imperfect, although by no 

 means so, I hope, in all ; but, although not so valuable as could be 

 desii'ed as an index of frequency, I venture to hope that the publi- 

 cation of the present collection will be found interesting to those 

 who have devoted any attention to this special department of Ana- 

 tomy. The importance attached to these variations must daily 

 increase in connexion with the absorbing interest of the study of 

 muscular morphology, and of the homologous elements thereof in 

 the various grades of the animal kingdom. Viewed from this stand- 

 point, an otherwise somewhat dry catalogue of variations in Human 

 Myology will be looked upon with favour by those who hail with 

 welcome the addition of every small contribution to the hourly 

 increasing treasury of our knowledge in this, one of the most 

 interesting departments of human study. 



Occipito-fro7italis. — The early removal of the brain prevented me 

 from examining this muscle completely, in a large proportion of the 

 subjects of oui' dissecting-room. The frontal portion I have seldom 

 found to agree completely with the description given in our standard 

 text-books, I have noted its pecuKarities in twenty-eight cases, in 

 which I examined it with special care. In only five of these did the 

 fleshy fibres reach so high as the coronal suture. Below I have 

 always found its fibres attached to the internal angular process of 

 the OS frontis, some being continued into the pyramidalis nasi, and 

 levator labii superioris alaeque nasi, but the great bulk of the fibres 

 blended with the orbicularis palpebranim and corrugator supercilii, 

 and a large proportion adhered to the deep surface of the skin of 

 the eyebrow. I could never satisfy myself of an attachment of any 

 of its fibres to the nasal bone, glabella, superciKary ridge, or supra- 

 orbital arch, as has been described by different observers. In every 

 case I examined, the deep surface of the muscle appeared to glide 

 freely over those bony prominences, and to be connected thereto 



