146 ELEMENTARY BIOLOGY. [CHAP. 



b. The moutJis of iJic cutaneous glands ; seen as 

 clear round spots, althougli iheir openings are 

 really triradiate : their number. 



ii. Preserve a piece of skin in alcohol of increasing 

 strengths, and stain with borax-carmine ; imbed 

 and cut sections perpendicular to its surface : 

 mount in Canada balsam. Examine under a low 

 power. 



a. The epidermis ; tlie superficial thinner and deep 

 stained portion. 



If. The dermis; the deeper main mass, for tlie 

 most part lightly stained. 



c. Pigment; most marked as a conspicuous ir- 

 regular black layer, in the superficial stratum 

 of the dermis. 



d. Cuta?ieous glands ; seen in section as numerous 

 large oval, rounded, or flask-shaped spaces, lying 

 within the dermis. Many can be seen to open 

 on the free surface by a narrow neck. 



iii. Examine under a high power. 



a. The epidermis {stratified efit/ielium). '\\'ork 

 from within outwards ; there will be found in 

 order : 



a. The Afa/pighia?t layer ; composed of a usu- 

 ally single basal row of close-fitting columnar 

 cells, each with an oval nucleus ; and of a 

 superficial main mass, consisting of several 

 rows of rounded or oval cells whose long 

 axes are parallel with the free surface. Small 

 l^igment granules are frequently aggregated 

 around the nuclei of the latter. 



