MR WM. TURNER ON VARIABILITY IN HUMAN STRUCTURE. 



185 



Fig. 9.* 



The lumbricales muscles presented many variations, some of the leading forms 

 of which it may be advisable to particularise, more especially that Froment 

 (with whom Henle seems to agree) states that variations in the arrangement of 

 these muscles are extremely rare. The first lumbricalis, in the specimens under 

 analysis, arose sometimes from the tibial side of the deep 

 tendon for the second toe, after the junction of the connect- 

 ing slip from the flexor hallucis with the division of the com- 

 mon flexor tendon for that toe. Sometimes only from the 

 tibial side of the connecting slip ; sometimes only from the 

 division of the common flexor to the second toe ; in one case 

 from the expanded part of the common flexor before it divided 

 into its terminal tendons ; in other cases by a continuous origin 

 both from the tibial side of the second toe tendon, and from 

 the expanded part of the common tendon ; and in two cases 

 by two distinct heads, — one from the tibial side of the con- 

 necting slip from the flexor hallucis, the other from the 

 expanded part of the common flexor before its division into 

 the terminal tendons. In one case no lumbricalis was present in the first meta- 

 tarsal space, but two were situated in the second space (fig. 8). In another case 

 the second lumbricalis was absent. In several cases, not only did the second, 

 third, and fourth muscles arise from adjacent sides of the tendons between which 

 they were situated, but also from special slips derived from those tendons. 

 Sometimes their fibres of origin extended for some distance backwards over the 

 general expansion of the common flexor tendon. In other instances the fibres of 

 the fourth lumbricalis, or of the third and fourth lumbricales, were continuous 

 with (or received fasciculi from) those of the flexor accessorius ; in others they 



1st, A large slip springing from the inner side of the soleus, and passing quite distinct from the 

 tendo Achillis, to be inserted into the inner concave surface of the os calcis. 



2d, A muscle arising from the deep fascia of the back of the leg, and inserted into the inner side 

 of the os calcis, close to the inner head of the flexor accessorius ; this apparently constitutes the 

 accessorius ad calcaneum of Gantzer. 



3d, Two muscular bundles connected to the deep fascia of the back of the leg, one as high as the 

 middle of the tibia, the other close to the origin of the flexor hallucis longus from the fibula ; these 

 bundles united to form a muscle which passed beneath the internal annular ligament to the sole 

 where its tendon bifurcated, one slip joining the tendon of the flexor hallucis longus, the other the 

 tendon of the flexor communis digitorum. A corresponding arrangement was found in both limbs. 



4th, A well-marked muscle arose from the deep surface of the soleus tendon. It concealed the 

 tendons of the deep muscles, and the posterior tibial vessels and nerves in the lower third of the leg, 

 and was inserted into the deeper surface of the tendo Achillis, immediately above the os calcis. A 

 similar case to this has been described by R. Quain. 



Other irregularities in this locality have been recorded by Mayer, Rosenmuller, Gantzer, 

 Meckel, Hallett, Theile, Henle, and John Wood. 



* Fig. 9. d, the accessory muscle to the flexor accessorius. It has been bent out of its proper 

 direction so as to occupy less space in the wood block, e, the displaced fasciculus of the flexor 

 brevis for the little toe, which simply blends, without bifurcating with the deep flexor tendon for that 

 toe. 



