494 
MR. BOWMAN ON THE MINUTE STRUCTURE AND 
approximated and flattened in the direction of the length of the fasciculi, and expanded 
in their transverse direction. 
6. Such contraction may engage a few such particles only, or the whole fasciculus, 
may oscillate from end to end, without occurring at any special situations or intervals, 
and may be independent of immediate nervous co-operation. 
7. Rugce and zigzag inflexions are a mere consequence of the approximation of the 
extremities of a fasciculus, otherwise than by its own contraction, and are necessarily 
obliterated by either its own contraction, or its elongation by other forces. 
8. It is highly probable, that in all contractions of voluntary muscle in the living 
body, the same mechanism is employed as in the dying ; and that in the living body, 
these contractions engage only parts of fasciculi at a time, and oscillate along them, 
as well as occur alternately in different sets of fasciculi. 
9. These results are true as regards the vertebrate and articulate classes of the 
animal kingdom. 
I remain, yours very truly, 
King's College, London, William Bowman. 
June 18, 1840. 
Postscript. 
Having in the foregoing paper argued that the contractions of living muscle must 
be the same in kind with those everywhere noticed by me in animals during the last 
moments of life, I have now to add the confirmation of direct observation with 
regard to this point. In the striated fasciculi of the legs of the Monoculus, and of the 
Argulus, voluntary contractions may be occasionally seen to occur ; a portion only 
of the fasciculus contracts, and may be known by its becoming broader and denser, 
and its transverse striae closer to one another and narrower than before. The effect 
of this is a shortening of the whole fasciculus and movement of the limb in corre- 
spondence. 
With respect also to the phenomena of contraction in muscle when removed from 
the body, 1 may observe that an opportunity of inspecting them in the human subject 
having lately presented itself, I have found them to be in every way identical with 
what had been previously observed in animals as herein detailed, and especially that 
when the fasciculi were immersed in water, bullae were developed upon them by the 
elevation of the sarcolemma, and their transverse striae were very much approximated 
to each other. (See fig. 79-) 
July 23, 1840. 
