218 



ANATOMY OF VERTEBUATES. 



Ill 



system of converging fibres 

 takes its origin from the 

 scapula itself, and converges 

 to an insertion close to that 

 of the preceding. The entire 

 mass of the muscles 22 and 

 11 antagonise that, 16, ica, 

 below ; one raises, the other 

 ^ji depjrcsses, and both rotate, 

 '*'' the humerus to and fro. As 

 the fore-limb gains size and 

 power in higher air-breathers, 

 the muscle 11 seeks a more 

 extended origin, covers a 

 greater proportion of the seg- 

 mental system of trunk- 

 muscles, acquires the name 

 of latissiinns dorsi, and, in 

 Anthropotomy, is classed 

 amongst the ' first layer of 

 the muscles of the back.' The 

 muscle 22, becomes deve- 

 loped into ' supra- ' and ' in- 

 fra-spinafus,^ and, perhaps, 

 also deJ/o'idcs. The pro- 



tractor scajiiihp, arising, as in 

 Fishes, from the paroccipital, 

 now also derives fi1)rcs from 

 the transverse processes of the 

 first and second truidv-verte- 

 bra;, and divides into two dis- 

 tinct liisciculi ; one, fig. 140, 



19, is inserted into tlie base 

 of the scapula ; the other, ib. 



20, into the humeral end of 

 that bone. A small strip, is, 

 which tends more directly 

 to raise the scapida, arises 

 from the transverse proces- 

 ses of the third vertebra : but 

 tlie muscle, i;i, is tliat wliich 

 l>est answers to the Irrtitor 

 scapuhc of Mammals. Two 



