72 MR. BOWMAN'S ADDITIONAL NOTE ON THE CONTRACTION OP MUSCLE. 



tween the primitive fasciculi, and inosculate with one another by very frequent 

 transverse branches, which complete the vascular web, and serve to attach its several 

 parts to the primitive fasciculi which occupy its interstices. 



Lastly, all the specimens of bloodless tetanic muscle which I have seen, have pre- 

 sented this striking peculiarity : — that the pallor has not occupied the whole muscle, 

 but patches of it, comprehending a portion of many primitive fasciculi, but not the 

 entire length of any, — a fact tending to the same conclusion. 



What has now been advanced, seems to render it —as it appears to me — certain, that 

 the tetanic spasm has consisted in contractions engaging only parts of each primitive 

 fasciculus at a time, and if so, of course changing their place, in order to bring every 

 portion into use in its turn. Whether the primitive fasciculi alternate with one 

 another in their contractions, is an obscure question, on which these observations 

 shed no light. 



It may be urged, however, that, even granting this conclusion true, it is unsafe to 

 argue concerning the healthy and moderate actions of an organ from the phenomena 

 it presents when in a morbid state. But the weight of this objection is more appa- 

 rent than real, for in a physiological point of view, the contractions of tetanus differ 

 from those properly termed voluntary, only in being uncontrollable by the will and 

 excessive in amount and duration. In violent tetanic spasm, I have myself ascer- 

 tained that the peculiar sound of voluntary contraction is audible in the part, and 

 identical with the normal sound ; and the appearance and feel of a muscle thus rigidly 

 convulsed, can be perfectly simulated for a short period by an act of volition*. 



I therefore conclude, from the whole of the preceding remarks, combined with the 

 facts and arguments advanced in my former paper, that the contraction of voluntary 

 muscle is not a sustained act of the whole congeries of contractile elements composing it ; 

 hut a rapid series of partial acts, in which all duly share, becoming hy turns contracted 

 and relaxed. 



King's College, London, 

 April 6, 1841. 



The figure represents a portion of a primitive fasciculus, taken from among many 

 others, from the complexus muscle, where it was ecchymosed and had lost in a great 

 measure its fibrous appearance. At (a) a fusiform contracted portion, with the striae 

 remarkably close. On either hand the sarcous elements are much stretched (b), or 

 even entirely disarranged (c, c, c), while at (d) there is a transverse rupture within 

 the sarcolemma, and at (e) this sheath itself has given way. 



* I yesterday, in company with my friend. Professor Todd, discovered the same appearances of partial con- 

 tractions in the recti muscles of the abdomen, ruptured by violent straining in diarrhoea. The voluntary 

 muscles of the whole body were infested with the Trichina Spiralis, and were enfeebled. — August 2, 1841, 



