HISTOLOGY OF THE FLEXOR TE^DOX 



187 



In all sections, whetlier of the disc or of the keel, there is a central portion or 

 flattened core which can easily be recognized by a hand lens and sometimes with the 

 naked eye. The portions of the disc and keel, external to this core, consist essentially 

 of a network of fibres which cross each other at right angles. One set of fibres, — the 

 longer ones — run parallel with each surface of the disc, and extend from the keels to 

 the edge of the leaf-like disc. The other set run at right angles to the surfaces of 

 the disc and extend from the flattened core to the surface. 



The most prominent feature in all the sections under low powers of the micro- 

 scope is their laminated structure. The laminae resemble stratified limestone or 

 stratified clay. In the greater part of the disc, the layers are evenly disposed upon 

 one another and are parallel to the upper and lower surfaces, but in the keels and in 

 the disc nearest t-^ the keels the stratification is wavy, but this appearance may be 

 an artefact. 



'^smmm ^- -fe^^^^y^ 



_Z^:_-zi_ll. 





m^si ^^i^->^M^i^:'J(y^'^. y//:^y^^ . 



Lowee^. surface 

 Figr. 6 shows file even laminated structure or stratification in tlie disc portion of tiie tendon. 





■J V 



Fig. 7 sliows wavy stratification. Low power. 



In a medium-sized animal the laminae of the disc vary in number from 20 to 40 

 above and below the flattened core, being more numerous in the middle of the disc 

 and decreasing towards the circumference, where their number may not exceed from 

 2 to 5. 



The laminae vary in colour from almost black to grey, shading to white. These 

 differences are probably due to the fact that all of the sections were prepared by 

 grinding on an emery wheel in much the same way as rock sections are made. Conse- 



