188 ON CERTAIN MUSCLES OF BIRDS. 
culties connected with the dissection of any special soft part to a 
minimum; and in the present communication the results are recorded 
of my dissection of the region of the thigh of the birds which have 
passed through my hands. In this region there are six muscles, or 
well-defined portions of muscles, which may or may not be present; 
and my chief object has been to note their presence or absence, 
which in some cases is far from easy, as modifications may occur 
which disguise the true connexions of a muscle, and thus lead to 
misinterpretation. 
As a common Fowl happens to possess all these six muscles well 
developed and easily demonstrable, I will commence with a short 
Page 627. account of their condition and relations in it, from which a correct 
idea may be easily formed of their situation in other birds with the 
help of the accompanying details. 
In commencing the dissection of the leg of a Fowl in order most 
easily to observe the arrangement of the muscles about to be described, 
Fig. 1. 
Outer view of right thigh of Gallus bankiva, partially dissected. 
s, sartorius; v e, vastus externus; 40 and 07, biceps, origin and insertion; Z/, 
tensor fascie; fc, femoro-caudal; a/c, accessory femoro-caudal; st, semi- 
tendinosus; ast, accessory semitendinosus; sm, semimembranosus; Ad, ad- 
ductor; P, pubis; R, rectrices. 
