FASCICULI. 



109 



nerves in their ramifications between these parts. The relation of 

 these different subdivisions of a muscle to each other, as well as the 

 shape of the fasciculi and fibres, is well shown by a transverse section 

 (figs. G4: and 65). 



Fig. 64. 



Fig. 65. 



Fig. 64. — A, Small Portion of Muscle, natural size; B, the same magnified 

 5 Diameters, consisting of larger and smaller Fasciculi, seen in a Transverse 



Section. 



Fig. 65. — A FEW Muscular Fibres, being part op a small Fasciculus, magnified, 

 siiu\yiNG THE Transverse Stri.e. 



a, eud view of b, h, fibres ; c, a fibre split into fibrils. 



Fasciculi. — The fasciculi are of a prismatic figure, and their sections 

 have therefore an angular outline. The number of fibres of which 

 they consist varies, so that they differ in thickness, and a large fasciculus 

 may be divisible into two or three orders of successively smaller bundles, 

 but of no regularly diminishing magnitude. Some muscles have large, 

 others only small fasciculi ; and the coarse or fine texture of a muscle, 

 as recognized by the dissector, depends on this circumstance. The 

 length of the fasciculi is not always proportioned to the length of the 

 muscle, but depends on the arrangement of the tendons to which their 

 extremities are attached. When the tendons are limited to the ends of 

 a long muscle, as in tlie sartorius, the fasciculi, having to pass from 

 one extremity to the other, are of great length ; but a long muscle may 

 be made up of a series of short fasciculi attached obliquely to one or 

 both sides of a tendon, which advances some way upon the surface or 

 into the midst of the fleshy part, as in the instances of the rectus 

 muscle of the thigh, and the tibialis posticus. Muscles of the kind 

 last referred to are named "' penniform," from their resemblance to the 

 plume of a feather, and other modifications of the arrangement, which 

 can be readily conceived, are named " semi-penniform " and " com- 

 pound penniform." Many short fasciculi connected thus to a long 

 tendon, produce by their combined operation a more powerful effect 

 tlian a few fasciculi running nearly the whole length of the muscle ; 



