Chap. I. RUDIMENTS. 19 



plete suppression of a part, already useless and much 

 reduced in size, in which case neither compensation nor 

 economy can come into play, is perhaps intelligible by 

 the aid of the hypothesis of pangenesis, and apparently in 

 no other way. But as the whole subject of rudimentary 

 organs has been fully discussed and illustrated in my 

 former works, 20 1 need here say no more on this head. 



Eudiments 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 lower ani- 

 mals 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 panniculus carnosus. Remnants of this muscle 

 in an efficient state are found in various parts of our 

 bodies ; for instance, 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 situa- 

 tions, namely in the axillae, near the scapulae, &c, all of 

 which must be referred to the system of the panniculus. 

 He has also shewn 22 that the musculus sternalis or ster- 

 nalis brutorum, which is not an extension of the rectus 

 abdominal is, but is closely allied to the panniculus, oc- 



20 ' Variation of Animals and Plants under Domestication,' vol. ii. 

 pp. 317 and 397. See also 'Origin of Species,' 5th edit. p. 535. 



21 For instance M. Richard (' Annales des Sciences Nat.' 3rd 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 

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

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

 more or less rudimentary condition. 



22 Prof. W. Turner, ' Proc. Ptoyal Soc. Edinburgh,' 18GG-G7, p. Q5. 



c 2 



