243 Mr. J. Wood on Variations in Human Myologij. [June 31, 



which all except 7 were found in the arms (including the levator claviculas)y 

 5 in the legs, and 2 in the head and neck. "With the exception of the le- 

 vator claviculce,costo-fascialis,BXidi sujora-costalis, found in the last-mentioned 

 subject, but not in No. 32, the correspondence (especially in the arms) 

 between the different lines of abnormal departure also is sufficiently close 

 to become significant, as the reader will have gathered in going through 

 the preceding pages. In subject 4 of the Table, which presented the 

 only specimen of the levator claviculce found this session, only one other 

 abnormality was found, viz. the abductor of the fifth metatarsal bone. 

 This was also found associated with it in last year's subject, which pre- 

 sents otherwise a marked contrast in the number of its abnormalities. 



In Nos. 5 and 7, the one a male tsnd the other a female, there are 

 nine variations respectively, of which, iii No. 5, there is but one which 

 is not in the arm ; and in No. 7, four in the legs and three in the arms. 

 In No. 2 are eight abnormalities, of which six are in the arms and the 

 rest in the legs. In No. 26 are found seven, of which three are in 

 muscles belonging to the upper extremity, and four in the legs. In 

 No. 13 are six, all in the arms. In thirteen subjects none were found 

 in the legs ; and in four they were found in the legs only, to the ex- 

 tent, in one case, of four examples ; and in all four subjects highly cha- 

 racteristic. None were found in the head, neck, or trunk only*. 



The extent of correspondence in combination of varieties in the subjects ar- 

 ranged in theTable(taken in the horizontal lines) cannotbesaid to be striking. 

 The variations seem to crop out here and there without much reference to 

 each other. This may, however, be partly owing to the comparatively small 

 number reviewed, and we should scarcely be safe in drawing deductions from 

 it before a much greater number of subjects are treated in a similar way. 



The correspondence seems to be the greatest in the arm and hand, which 

 here also assume a prominence over the rest of the frame. This, however, 

 may be due to the greater number of instances found in the upper extremity. 



* In estimating the proportion of the abnormalities contained in the Table, the 

 numbers and names at the head of the columns, together with those down the miscel- 

 laneous columns, must be compared with the total number of the muscles in the cor- 

 responding parts of the human body. Thus, taking the number of the voluntary- 

 muscles of the head, neck, trunk, and perineum, excluding those of the back, internal 

 ear, larynx, and the intercostals (as subject to minor irregularities which have not been 

 noted), we have about 72. Comparing these with the kinds of variety in the Table, 

 viz. 10, we have a proportion of about 1 in 7. In the upper extremity we have 60 

 -muscles; of lines of variation we have 26, or nearly half. In the lower extremity we 

 have 61 muscles; of varieties 14, or not quite one-fourth. 



The varieties classed in the Table include the greater number of those that have been 

 previously observed by the author and others. Ten only, which have been mentioned 

 in former papers as being subject to other irregularities than duplication and de- 

 ficiency, are absent from this list. 



This clearly shows that notable departures from the ordinary type of the muscular 

 structures run in definite grooves or directions, which must be taken to indicate some 

 unknown factor, of much importance to a comprehensive knowledge of general and 

 scientific anatomy. 



