384 



THE TISSUES. 



Fig. 242. 



muscular) fibre-cells;" since in case of both, cells are found, more 

 or less elongated into the form of fibres. Only two varieties, there- 

 fore, of muscular tissue need be recognized; viz., the fibre-cells 

 just mentioned, and the striated muscular fibre. 



I. THE CONTRACTILE, OR MUSCULAR, FIBRE-CELLS. 

 The larger fibre-cells have generally been named smooth, or non- 

 striated, muscular fibres, and have been described as jointed fibres, 

 presenting nodosities, as represented in Fig. 242. This is, however, 

 their appearance, very nearly, when acted upon by water. An ac- 

 curate description of them was first given by Kolliker. 



The muscular fibre-cells are from g^ to 3^ of an inch long, by 

 guW to 40*00 f an i ncn broad; and are composed of a soft, nearly 

 homogeneous light-yellow substance. The nuclei are visible only 

 when acted upon by acetic acid, and are usually long and staff-like, 

 as seen in Fig. 243, which also shows the usual long and slender 



form of the cells. Very sel- 

 Fig. 243. ^ om a nuc ] eo i us exists in the 



nucleus, and the latter is al- 

 ways in the middle of the 

 fibre. The substance of the 

 cell sometimes exhibits pale, 

 dark granules, partially ar- 

 ranged in rows parallel to 

 the axis of the cell; but, in 

 other respects, the cell, like 

 the nucleus, is homogeneous 

 and hyaline. 



It is, however, doubtful if 

 any cell-membrane exists. 

 Kolliker thinks he has seen 

 it in some individual fibres; 

 but Lehmann cannot demon- 

 strate its existence chemi- 

 and concludes that 

 fibres 



are never ll- 



Fig. 242. A. A non-striated muscular fibre from the 

 urinary bladder. Two of the nuclei are seen. B. A 

 non-striated muscular fibre from the stomach. The 

 diameter of this and the preceding fibre, midway be- 

 tween the nuclei, was 1-1750 of an inch. (Magnified 600 closed by a true 



^mFusiformcellsofsmoothmuscularfibrefrom Sh Uld hlS Opinion ^ <*e- 



the renal vein of man. a. Two cells in their natural niOnstrated to be Correct, the 



state, one of them showing the staff-shaped nucleus, b. . /j? 77 , i 



A cell treated with acetic acid, with a nucleus, a, c, term M r *"<*tt mUSt b a g am 



brought strongly into view. replaced \>y fibre merely. We 



