476 MUSCLES. 



attended with an active enlargement of the organ forcing it 

 energetically against the hand if placed upon it. 



We will now consider the anatomy and physiology of the ultimate 

 muscular fibre. Mr. Hare affirms that, in the field of a moderately 

 powerful microscope, a muscular fibre evidently appears made up 

 of numerous minute tubes, each exhibiting longitudinal striae with 

 transverse bands ; the average diameter of each of these ultimate 

 fibres or tubes being T J T of an inch.P Under contraction, the por- 

 tions between the transverse bands draw the latter nearer together, 

 and, swelling out, seem girted by them, so that the whole fibre some- 

 what resembles a string of eggs. This appearance, Mr. Hare sup- 

 poses, led Dr. Croon to adopt the idea that the ultimate fibre of 

 muscle was constituted by a chain of bladders filled with fluid. 

 In fact, Mr. Bauer thinks he discovers muscular fibres to be chains 

 of globules 9, and Prevost and Dumas declare the same from their 

 microscopic observations. 1 " The muscular tubes are represented 

 by Mr. Hare as filled with a matter which causes them to appear 

 solid till it is liquefied by heat : Mascagni describes the muscular 

 fibre as a small cylinder, filled with glutinous matter. 8 Fon- 

 tana asserts that the primitive muscular fibre is marked by con- 

 tinual minute crispations and nodosities, and that it pursues a 

 straight course, but is solid like the tendinous. Meckel, Rudolphi, 

 and Tiedemann believe the primitive muscular fibre solid. Dr. 

 Hodgkin found it not to consist of globules, and to be marked 

 by transverse lines, which he thinks distinguish muscular from all 

 other fibres. Raspail, like Mr. Hare, corroborates the assertion 

 of Mascagni. He declares that every muscle, like the adipose 

 texture and vegetable organs in general, consists of cells inclosed 

 within each other in an indefinite series ; but that, whereas their cells 

 approach to a spherical form, those of muscle are cylindrical. The 

 ultimate cylinders are closely applied to each other in very loose 

 spirals round an imaginary axis ; and each is full of a substance not 

 completely miscible with water ; and here and there globules ap- 

 pear irregularly, in contact with the inner surface. In the bullock, 



p Thomas Hare, A View of the Structure, Functions, and Disorders of the 

 Stomach, $c. p. 28. sq. 1821. 



<i Phil. Trans. 1818. J. F. Meckel, by microscopical observations, fancies 

 the muscular no less than the nervous fibre, and the substance of the liver, kidney, 

 spleen, &c., to be globular. 



r Annales de Ckimie, t. xviii. * Prodrome, p. 97. 



