-^Uv 



64 CONXECTIVE TISSUE. 



cross sections of a tendon or ligament present different figures of the 

 sectional areas of the bundles. A sheath of dense areolar tissue covers 

 the tendons and ligaments on the outside, and a variable amount of the 

 same tissue lies between the larger fasciculi ; little in tendons, more in 

 some fibrous membranes. 



The surface of a tendon or of any other part consisting of this 

 texture, appears marked across the direction of the fasciculi with 

 alternate light and dark streaks, which give it a peculiar aspect, not 



unlike that of a 

 Fig- 36. watered ribbon. 



This appearance 

 is owing to the 

 wa^^ course of the 

 filaments, for when 

 the light falls on 

 them their bend- 

 ings naturally give 

 rise to alternate 

 lights and 



Q K\ o ri ATirc 



Fig. 86. — Tendon of Mouse's Tail, stained avith Loa- , „ ' ' ^ _ ^ 



WOOD ; SHOWING CHAINS OF CeLLS BETWEEN THE TeNDON- ^^ ^ Very UUe 



Bundles. 175 diameters. tendon, such as 



those in the tail 

 of the mouse or rat, or a portion only of a larger one, is examined 

 under the microscope in an indifferent fluid, and a little dilute acetic 

 acid is cautiously added, the filaments are seen to swell up and become 

 indistinct, and the. acid discloses the existence of chains of oblong flat- 

 tened cells lying between the tendon-bundles (fig. 36). These cells, 



Fig. 37. 



Fig. 37. — Eight Cells from the same Tendon as repkesented in Fig. 36. 



425 diameters. 



The nuclei, with their numerous nucleoli, were deeply coloured by the logwood. 



which are represented more highly magnified in fig. 37, agree, in 

 almost every point except in shape, with the connective-tissue cor- 

 puscles previously described : each consists of a delicate protoplasmic 

 body, thicker at the centre than at the sides, and containing a more 

 or less flattened, round, or oval clear nucleus, with several nucleoli. 

 The ends of adjacent cells are in close apposition, so as to form, as 

 before noticed, long chains of cells in the tendon, and the nucleus 

 is generally so situated towards one end of the cell as to be in close 

 proximity to the nucleus of an adjacent cell ; they thus present the 

 appearance of being arranged in pairs. Here and there a third nucleus, 

 with a small amount of protoplasm, may be seen interpolated ])etween 

 two such cells (fig. 3G). The rows of cells lie flattened against the 

 tendon-bundles, the middle of each cell lying in the angular space 

 between three or more bundles and a lamellar prolongation extends 



