126 ELEMENTARY BIOLOGY. [CHAP. 



/?. The cells ; flattened and close fitting ; irregular 



in outline, as may be seen on following a. 

 y. The cell structure ; protoplasm differentiated into 



ecto- and endoplasm (cf. supra) ; nucleus central, 



oval or rounded. 

 8. Look for lymph stomata ; perforations of the 



membrane, each surrounded by small more 



deeply stained cells. 

 d. Stratified epithelium ; see epidermis 15. iii. 



3. Connective tissue. 



Of these there are two main varieties, a. and b. 



a. White fibrous tissue. This occurs typically in 

 tendons, but is widely distributed throughout the 

 body, mixed with other tissues. Tease out a bit of 

 fresh tendon in water : examine with a high power. 



a. It is chiefly made up of very fine wavy fibres 

 which, in the aggregate, impart a glistening 

 white colour to the tissue {(white fibres) ; they 

 run in bundles parallel to one another and do 

 not branch. 



/?. Treat with dilute acetic acid. Most of the above 

 disappear, but a few well-defined curled fibres 

 (yellow elastic fibres) remain. Besides these 

 some small elongated and granular proto- 

 plasmic masses are brought into view (con- 

 nective-tissue corpuscles). 



b. Areolar tissue. Lay bare the muscles of the hind- 

 limb ; sheets of areolar tissue will be seen passing 

 between them and the integument. Remove one 

 of these, being careful to avoid undue stretching 

 and transfer to a slide: examine in water. 



