528 



MUSCULAR MOTION. 



scope."' Previous to him no author appears 

 to have examined them. But Leeuwenhoek,f 

 his friend and correspondent, makes continual 

 mention of his examinations of the muscular 

 fibre of various animals. This acute and en- 

 thusiastic observer clearly recognized the im- 

 portant fact, that each elementary fibre is a 

 perfect and separate organ in itself; he was 

 astonished to find that in all animals, the 

 largest as well as the smallest, these fibres are 

 excessively minute ; he discovered the manner 

 in which they are aggregated, and invested by 

 areolar tissue; and by boiling and drying a 

 muscle and then making tranverse sections of 

 it, he ascertained those of voluntary muscle to 

 be polygonal and solid. He described the cross 

 lines, which he conceived to be on the surface 

 only and to be the coils of a spiral thread. 

 To this structure he attributed the active power 

 of the fibre, comparing it to an elastic coil of 

 wire. lie further saw the longitudinal lines 

 visible on the elementary fibre, and considered 

 them to be an evidence of a still minuter com- 

 position by filmllae. All these points are well 

 illustrated by figures, which leave no doubt of 

 his meaning; but, as his results are scattered 

 through a great number of letters, much of 

 what he accomplished seems to have been over- 

 looked by later writers. Leeuwenhoek con- 

 cluded that in contraction the cross markings 

 approximate, but I cannot discover that he 

 speaks of having seen this. He confounded 

 the cross markings seen on tendon with those 

 of muscle, and fell into the prevalent error of 

 attributing contractility to the tendons. Mal- 

 pighi incidentally mentions the minute structure 

 of muscle in only one passage of his works. J He 

 appears to have seen the transverse stripes of the 

 elementary fibre,andtohave also likened them to 

 those of tendon. Contemporary with Leeuwen- 

 hoek was de IIeide, who, in 1698, published 

 some observations on muscular fibre, describ- 

 ing and figuring the transverse markings. In 

 1741, Muys,|| in a voluminous work, with 

 good plates, gave all that was previously known, 

 and added many observations of his own. His 

 book, however, is learned rather than profound. 

 He separates the elementary fibres into the 

 simple and reticulated, and seems to have con- 

 sidered the stripes to be the effect either of mi- 

 nute zigzags during contraction or of a spiral 

 form of the fibrillie. 



Prochaska^I next produced an excellent trea- 

 tise on muscle, in which he explained, with 

 great clearness, the figure, size, and solidity of 

 the elementary fibre, and the appearances of 

 the fibrillae into which it divides. He fell into 

 the error, however, of confounding the trans- 

 verse markings in the intervals of the discs, 

 with other creasings or flexuosities which never 



* Posthumous Works by Waller, 1707, Life, 

 p. xx. 



f Epist. Physiologic*, passim. 



| De Bombyce, p. 9, 10, written before the 

 year 1687. 



$ Experimenta circa sanguinis missionem, fibras 

 motrices, &c. Amstel. 1698. 



[I Investigatio fabrics, &c. Lugd. Bat. 1741.' 



Tf De carnc musculari. Viennae, 1778. 



exist in the living boJy, but continually pre- 

 sent themselves, in the dead fibre, from me- 

 chanical causes. All these he attributed to 

 lateral pressure made on the fibre and fibrillae 

 by vessels, nerves, and areolar tissue, which 

 he erroneously imagined to penetrate the inte- 

 rior of the fibre. Prochaska injected muscle 

 with great success,* and found the vessels so 

 numerous that he was induced to believe con- 

 traction to depend on distension of the vessels, 

 throwing the fibrillae into zigzags. 



Fontana,-}- a few years afterwards, gave a 

 much more accurate account of the fibre than 

 had previously appeared, and one remarkable 

 for its simplicity. According to him the ele- 

 mentary fibre consists- of fibrillae, marked at 

 equal distances by dark lines, which by their 

 lateral apposition occasion the appearance 

 of cross striae. Hence he styled the fibre a 

 primitive fasciculus. By this term, which has 

 been generally adopted, undue importance is 

 attributed to the longitudinal cleavage, for the 

 elementary fibre may as justly be called a pile 

 as a bundle. It is not, however, in strictness, 

 either one or the other. 



In the period that has elapsed since Fon- 

 tana's description was published, up to the 

 last few years, no real addition has been made 

 to our knowledge, and so discredited or for- 

 gotten, at least in this country, were the labours- 

 of the authors already enumerated, that the 

 anatomy of the muscular fibre was taken up 

 as a new inquiry in 1818 by Sir Everard Home 

 and Mr. Bauer. \ The latter very excellent 

 observer must have been deceived by the im- 

 perfection of his glasses, which do not seem to 

 have been adapted to so minute a structure, 

 for his results, as published by Sir E. Home, 

 have had the effect of retarding rather than of 

 advancing our knowledge, by raising doubts as 

 to the credibility of any conclusions founded 

 on microscopical research. In 1832, Dr. 

 Hodgkin and Mr. Lister re-discovered the 

 transverse markings on the elementary fibre of 

 voluntary muscle and of the heart, and pointed 

 out, as Muys and Fontana had done, that 

 their presence was a character by which this 

 could be distinguished from the fibre of the 

 uterus, bladder, &c., which latter they con- 

 sequently denied to be muscular. Since then, 

 many inquirers, both in this country and 

 abroad, have taken up the subject with im- 

 proved instruments. 



Among those who have arrived at conclu- 

 sions similar to those of Fontana may be men- 

 tioned the names of Lauth, Muller, Schvvann, 

 and Henle. Others, however, have entertained 

 very opposite and, as 1 believe, erroneous views 

 of the composition of the fibre. Mandl^I con- 

 ceives the cross markings to be produced by a 



* Some of these preparations were lately shewn 

 me by Baron Larrey, to whom, they were presented 

 by Prochaska himself, during the occupation of 

 Vienna by the French. 



t Sur le Venin de la Vipere, &c. 1781. 



t Phil. Trans. 1818 & 1826. 



$ Appendix to Translation of Dr. Edwards's work, 

 De 1'Influence des Ayens Physiques sur la Vie. 



IT Traite pratique du Microscope, p. 74-5. Paris, 

 1839. 



