J 



CONNECTIVE TISSUE. 



165 



In thin sections from a fresh tendon, or a tendon preserved in 

 chromic acid solution, either stained with chloride of gold or not, 

 we recognize with lower powers of the microscope that the tendon 

 is made up of bundles of a finely striated tissue. All bundles 

 are spindle-shaped, and vary greatly in size j they are separated 

 from each other by light interstices, in which, particularly in the 

 injected specimens, the blood-vessels are seen to course along and 

 around the bundles. The appearance of a bundle is striated as 

 long as the continuity of the tissue is unbroken. But where the 



IT 



FIG. 60. TENDON OF ACHILLES OF A YOUNG PERSON. 

 SECTION. CHROMIC ACID SPECIMEN. 



LONGITUDINAL 



, bundles of striated connective tissue, here and there finely dotted; TO, tendon 

 puscles within the bundles or between the smallest bundles ; IT, interstitial medul- 

 lary tissue carrying capillary blood-vessels, C. Magnified 500 diameters. 



>r has torn the bundle, isolated fibrillae appear, which, owing 

 their elasticity, retract and curl. (See Fig. 59.) 

 Higher amplifications reveal that the larger bundles divide 

 into a number of smaller ones, all of which exhibit a spindle 

 shape, and in correspondence with the boundary lines of the sec- 

 ondary bundles we see spindle-shaped plastids, either single or 

 in rows or chains, and either nucleated, and, as a rule, pale 

 granular, or reduced to the size of homogeneous or granular 

 nuclei. All of these are included under the term u tendon 

 corpuscles." In advanced age the apparently isolated nuclei 

 prevail, especially in the middle of the tendon, while in younger 



