Chap. I.] RUDIMENTS. 19 



Rudiments of various muscles have been observed in 

 many parts of the human body ; 21 and not a few muscles, 

 which are regularly present in some of the low x er animals 

 can occasionally be detected in man in a greatly reduced 

 condition. Every one must have noticed the power which 

 many animals, especially horses, possess of moving or 

 twitching their skin ; and this is effected by the pannicu- 

 lus carnosus. Remnants of this muscle in an efficient 

 state are found in various parts of our bodies ; for in- 

 stance, on the forehead, by which the eyebrows are raised. 

 The platysma myoides, which is well developed on the 

 neck, belongs to this system, but cannot be voluntarily 

 brought into action. Prof Turner, of Edinburgh, has 

 occasionally detected, as he informs me, muscular fasciculi 

 in five different situations, namely, in the axillre, near the 

 scapulae, etc., all of which must be referred to the system 

 of the panniculus. He has also shown 22 that the musculus 

 sternalis or stemalls brutorum, which is not an extension 

 of the rectus abdominalis^ but is closely allied to the 

 panniculus, occurred in the proportion of about three per 

 cent, in upward of six hundred bodies : he adds, that this 

 muscle affords " an excellent illustration of the statement 

 that occasional and rudimentary structures are especially 

 liable to variation in arrangement." 



Some few persons have the power of contracting the 

 superficial muscles on their scalps ; and these muscles are 

 in a variable and partially rudimentary condition. M. A. 

 de Candolle has communicated to me a curious instance 

 of the long-continued persistence or inheritance of this 



11 For instance, M. Richard ('Annales des Sciences Nat.' 3d series, 

 Zoolog. 1852, torn, xviii. p. 13) describes and figures rudiments of what 

 he calls the " muscle pedieux de la main," which he says is sometimes 

 M infiniment petit." Another muscle, called " le tibial posterieur," is gen- 

 erally quite absent in the hand, but appears from time to time in a more 

 or less rudimentary condition. 



29 Prof. W. Turner, 'Proc. Royal Soc. Edinburgh,' 1866-67, p. 65. 



