INYOLUNTAET MIJSCULAE TISSUE OE THE UEINAET BLADDEE. 
471 
each other, the closeness varying from i^th to ^ an inch. When a fasciculus is free 
for some distance from the usual communicating bundles, the tendons are about ^^th of 
an inch apart. In length they average i^th of an inch (varying from ^th to i^th) ; 
and their breadth, which is not quite so great as that of the bundles of fibres bearing 
them, ranges, according to the difference in size of the bundles, from lo i^th of 
an inch. 
On inspection with the naked eye or with a low magnifying power, the tendons may 
be seen to be formed of white threads, which project unequal distances amongst the 
fleshy flbres, each receiving a certain number of the fibres, and do not therefore give a 
defined transverse line across the muscular fasciculus. Under a low power of the 
microscope, the fleshy fibres, when traced onwards, may be observed to advance into 
the tendinous mass, and, becoming smaller and fewer in number, to leave a spot where 
only the common fibrous texture serves as the bond of union between the fleshy bundles 
entering the tendon at opposite ends. Commonly, however, some fleshy fibres will be 
seen extending all along the object under examination, in consequence of their reaching 
different distances in the tendon. How the muscular is connected with the fibrous 
tissue will be subsequently described. 
The tendons above noticed resemble those in the voluntary rectus abdominis muscle 
m then structm'e, though, from being placed at unequal distances on the fasciculi of the 
fibres, they do not form a transverse band as in that muscle ; and they are also like them 
in then use, ser\ing as fixed points for the contracting fleshy fibres. 
Similar tendinous points amongst the fleshy bundles of the oesophagus were described 
in my paper of 1856 : these reach entirely or only partly through the bundles of fibres, 
as in the bladder ; they measure in length -^th to ^^th of an inch, but in mdth only 
about -^th of an inch ; and they are distant -§• to 1^ inch from each other. In these 
both the voluntary and the involuntary fibres of the gullet are collected. 
Characters of the Muscular Fibres. 
When some fibres of a fasciculus of the bladder have been freed from the surrounding 
sheath and separated carefully from the rest, they will present the under-mentioned 
characters with an object-glass of |-th of an inch focus. 
Fmm . — The fibres are slender rounded strings, like the fibres of the voluntary muscle, 
and present at intervals corpuscles or nucleus-like bodies. If the object under examina- 
tion is but little disturbed in the attempts to detach it with needles, the pale fibres will 
appear generally of uniform width. With transmitted light the surface is distinctly 
granulous or longitudinally striated, and without a dark limiting border. On a cross 
fracture the end is either solid and dotted, or jagged with separate points, as in a fibre 
of the voluntary muscle under similar conditions. Not uncommonly many of the fibres 
under inspection are contracted here and there, and wavy at the narrowed part, as in 
Plate XXVI. fig. 3 a ; so that, supposing a fibre to be broken into pieces, the fragments 
would produce objects with pointed ends and nucleus-like bodies (fig. 3 ^), resembling 
3 Q 2 
