MUSCULAR MOTION. 



529 



Spiral thread of areolar tissue investing the 

 fibre, and Mr. Skey* describes them as an 

 external structure, independent of the fibrilla 3 , 

 which he believes to be arranged in band-like 

 sets around a glutinous substance in the axis 

 of the fibre. Ficinusf falls into the old error 

 of Prochaska, of imagining the striae to be the 

 result of minute flexures of the fibrilias, and, 

 like him, he confounds with them the secondary 

 flexures of the whole fibre. Hence, says he, 

 the appearance of globules or particles is false, 

 and only exists during contraction. Other 

 opinions still 1 have had occasion to allude to 

 in the course of the article MUSCLE, which, as 

 before remarked, is founded on observations 

 which have been now two years before the 

 public. J 



All the best observers are agreed as to the 

 existence of certain appearances, and the dis- 

 crepancies we encounter in the interpretation 

 of them ought not to bring discredit on all 

 researches of this sort. They place, indeed, 

 in a strong light the difficulty of the inquiry, 

 and the necessity for repeated, varied, and un- 

 biassed observation, with the best instruments 

 we can command. But we are too familiar 

 with conflicting and even opposite statements 

 concerning visible facts, occurring daily under 

 the eyes of every one, to suppose it possible 

 that any kind of investigation will ever be free 

 from those causes of error, which lie in man's 

 nature, in his own microcosm, and the effects of 

 which can only be neutralized by the common 

 consent of numerous independent observers. 

 As for those difficulties, whatever they may be, 

 which are inherent in the nature of the subject, 

 we cannot doubt that they will be, in due time, 

 appreciated and overcome. 



Some of the opinions concerning the nature 

 of contraction, entertained by the earlier ob- 

 servers, have been already mentioned; another, 

 which seems to have been grafted on the doc- 

 trine of the vital spirits, was, that these spirits 

 were directed into the fibres and distended 

 them, thus causing them to tumifyand shorten. 

 Accordingly, some (as Robert Hooke and 

 Cowper) considered each fibre or fibrilla to be 

 hollow; which need not excite surprise, when 

 we find the great Mascagni believing each to 

 be a lymphatic vessel. The first hint of another 

 very noted hypothesis is to be found in the 

 Memoirs of the French Academy, 1724: 

 L'Abbc de Molieres there says,|| " Les fibres 

 charnues qui s'etendent selon la longueur du 

 muscle, et dont le raccourcissement fait son 

 action, se divisent en un grand nombre de 

 petites fibres de meme nature longitudinales 

 aussi, et qui sont liees les unes aux autres par 

 des filets nerveux transversaux disposes le long 

 des fibres de distance en distance. De plus, 

 les petites fibres charnues ne sont pas droites, 

 mais pliees en zigszags, dont les angles se 



Phil. Trans. 1837. 



t De Fibrz Muscularis Forma et Structura. Lip- 

 siae, 1836. 



t Phil. Trans. 1840. 



Prodrome della grande Aaatomia da Franc. 

 Automarchi, Firenze, 1819. 



|| Malgaigne, Anat. Chirurgicale, vol. i. p. 102. 

 Paris, 1838 



VOL. III. 



Irouvent aux endroits, ou sont les filets trans- 

 versaux." Hales* examined the abdominal 

 muscles of small living frogs, and saw them 

 thrown into zigzags during contraction, as he 1 

 imagined ; but he mistook the uncontracted for 

 contracted fibres, as I have explained.! Pre- 

 vost and Dumas, at a later period,! described 

 the same zigzag flexure of the fibres during 

 contraction, and further imagined it to be an 

 electrical effect produced by the passage of the 

 nerves across them at their angles of flexure. 

 This doctrine was too captivating not to obtain 

 very general credence, especially as it seemed 

 to fall in with a notion, at that time very cur- 

 rent among speculative physiologists, that the 

 nervous influence is a form of electricity. But 

 its validity has of late begun to be questioned ; 

 Professor Ovven,^ in small filaria? and in a spe- 

 cies of vesicularia, observed a fact opposed to 

 it, viz. the bulging of the (unstriped) fibres near 

 their centre, without their falling out of the 

 straight line, in contraction. A similar fact 

 was observed in the case of the (unstriped) 

 muscles of the Polypifera, by Dr. A. Farre;|| 

 and Dr. Allen Thomson,^ on repeating the 

 experiment of Hales and Prevost on the Frog, 

 " observed single fibres continuing in contrac- 

 tion, and being simply shortened, and not fall- 

 ing into zigzag plicae ; and he was led to sus- 

 pect, from this and other circumstances, that 

 the zigzag arrangement was not produced until 

 after the act of contraction had ceased." M. 

 Lauth, after a careful investigation, concludes** 

 that a fibre may shorten with or without zigzag 

 inflection. Such, I believe, was the state of 

 this question in 1840, when I published the 

 observations,!! on part of which the account 

 of the nature of contraction, given in the pre- 

 sent article, is principally based. In the fol- 

 lowing year I addedJJ a note, on the appear- 

 ances met with in human muscle ruptured by 

 tetanic spasm, and which seemed to me to 

 prove that the conclusions I had previously 

 drawn from the phenomena of the rigor mortis 

 were true as regards the act of contraction, as 

 it occurs in the living body, 



BIBLIOGRAPHY. To the following works may be 

 added the several systematic treatises on descriptive 

 anatomy, and on general anatomy and physiology. 

 Hooke, Posth. Works, by Waller, 1707. Experi- 

 ments and Observations of Robert Hooke, &c. by 

 W. Derham, 1726. Malpighi, De Bombycibus, 

 p. 9, 10, Leetiwenhoek, Phil. Transact. 1674, 

 1677, 1683, &c. Epist. Physiolog. passim. De 

 Heide, Experimenta circa sanguinis missionem, 

 floras motrices, urticam marinam, &c. Amstelod. 

 1686 and 1698, Croone, De ratione motus mus- 

 culoturn, Lond. 1664. Aluys, An account of se- 

 veral observations concerning the frame and tex- 

 ture of the muscles, Phil. Trans. 1714. De car- 



* Haemastatics, p. 59. 



t Phil. Trans. 1840. 



j Majendie's Journal, 182$. 



Hunter's Works by Palmer, vol. v. p. 2612, 

 note. 



|| Phil. Trans. 1838,, pp. 394 and 396. 



5T Quoted by Owen, loc. cjtat. 



** L'Instiiut. No. 73, quoted by Miiller in his 

 Physiology, Baly's Transl., p. 888. 



ft Phil. Trans. 1840, pt. ii. 



ft Phil. Trans. 18.41, pt. ii. 



2 M 



