1867.] Mr. J. Wood on Variatmis in Human Myology. 54?! 



closely or identically similar origin to those heads of the muscle with 

 which they afterwards respectively united, may be considered as exten- 

 sions and separations of a portion of the fibres of those heads of origin, 

 Mr. Macalister mentions that in a male subject he found in both legs a 

 continuation of the tendinous ischial origins of this muscle over the 

 surface of the great sacro-sciatic ligament to the side of the sacrum, but it 

 does not appear that this constituted any approach to a distinct head. 

 But in the specimen under consideration, the abnormality is constituted 

 by a distinct muscular bundle, with an upper and a lower tendon, the 

 fibres of the former capable of being traced in those of the deep gluteal 

 fascia for a considerable distance. In the Dog the author has found the 

 almost exact counterpart of this third head of the 'biceps flexor cruris. 

 It is a deeply placed sleiider bp.nd of muscular fibres, arising from the 

 surface of the great sacro-sciatic ligament. It lies under the ischioi 

 origin, and becomes inserted into the fascia on the outside of the leg 

 below the main bulk of the widely-spread biceps proper. It is there con- 

 nected also with a fibrous sheath which invests the tendon of the^to- 

 taris. In this animal this musclar slip seems to represent the caudal 

 and sacral origin of the biceps in the B;odents, and other Mammalia. 

 The homology between the abnormal third heads in the human subject 

 and the caudal origin in animals was pointed out by Theile. 



In a muscular male subject was found an abnormality, in many 

 points resembling that described by Grantzer as the " Accessorius ad 

 calcaneum.^^ It was, however, very difli'erent in its origin to those 

 described by that author, although identical in its form and insertion 

 (fig. 7, a). A long slender tendon, very much resembling that of the 

 plantaris in its texture and appearance, was placed along the inner side 

 of it, so as to present the appearance of a double plantaris. This ten- 

 don was attached above to the upper third of the hinder surface of the 

 fibula, below the origin of the soleus (5), and crossed obliquely the pos- 

 terior tibial vessels, muscles, and aponeurosis, towards the inner mal- 

 leolus. At the lower third of the leg, a flat, ovoid, tapering, muscular 

 belly, 3 inches long and 1 inch wide, was developed upon it, and 

 became implanted by a short-spreading tendon upon the calcaneum, in 

 front and to the inner side of the tendo-achillis, about three-quarters 

 of an inch distant from it. From the lower part of it* outei* border the 

 muscle sent off a tendinous slip, which joined the plantaris tendon in 

 a mass of fibro-fatty tissue placed above the bursa of the tendo-achillis. 

 Hyrtl has mentioned the occasional occurrence of a muscle some- 

 what resembling this, as arising from the popliteal (?) fascia, or lower 

 part of the fibula, and inserted into the calcis. This Henle seems to 

 consider as an abnormal plantaris. In the case just described, however, 

 the size, shape, and position of the muscular belly, and the insertion of 

 the lower tendon so much resemble the muscle described by Gcintzer, 

 and also that figured by the author in his paper of 1864, that he has no 



