CLASSIFICATION OF ANIMAL PREPARATIONS. 437 



Muscular Fibre. — The mode of preparing this highly in- 

 teresting tissue has already been given at page 360, it only 

 remains in this place to add a list of the animals from which 

 the most instructive preparations may be procured. The 

 capillary vessels of muscle, as stated at page 360, may be seen 

 in the thin muscles of the eyes of birds and smaU mammalia, 

 but they are best studied after injection : — 



. The above list includes only muscular fibres of the striped 

 kind, or what are termed voluntary, in contradistinction to 

 others which are unstriped or involuntary; amongst the latter 

 class, however, are generally mentioned the fibres of the 

 heart of different animals; although these have transverse 

 strife, the organ itself, nevertheless, is an involuntary one. 

 The muscular coat of the entire alimentary canal, with the 

 exception of the upper part of the sesophagus, is whoUy sup- 

 plied with involuntary fibres, and from any part of the tract 

 specimens may be taken. The fibres, with the exceptions 

 above noticed, differ from those of voluntary muscle, in being 

 much smaller, and also in the absence of strife. The subjoined 

 list will give the localities of both kinds : — 



Nearly allied to involuntary muscular fibre, is a fibrous 

 tissue termed the yellow or elastic ; this is often found in 

 connection with another finer and less elastic, and called, from 



