THE SKIN 101 



11. Arrector pili mtiscle. (Nearly always to be found stand- 

 ing obliquely to the divided hair -follicle. 



(H.)* 



12. (If demonstrable:) (a) The stratum lucidum. (b) Stra- 

 tum granulosum. 



13. The columnar cells of the rete, next the corium. 



14. (Where the tissue has been torn:) The impacted cells of 

 the horny epidermis. 



15. The basement membrane covering the corium. 



16. Capillaries of the papillae of the corium. (These may be 

 distinguished, when seen longitudinally, by tortuous lines of 

 elongated and deeply stained nuclei belonging to their endothelium. 

 Arterioles may be differentiated by their long muscle cells, the cir- 

 cular fibers lying transversely to the vessel.) 



17. The root-sheath of the hair-follicles. (The cells compos- 

 ing the root -sheath vary in appearance, according to their position 

 relatively to the hair; and this will enable you to demonstrate two 

 layers, or an inner and an outer root -sheath.) 



18. The glassy membrane of the hair-follicle. (Appearing 

 simply as a clear space between the root -sheaths and the outer 

 fibrous coat.) 



19 . The intra-cellular network in the large polyhedral epithelial 

 cells of the sebaceous glands, and the minute fat- globules in the 

 same. 



20. The nuclei of the fat-cells in the adipose tissue. (They 

 appear pressed to one side.) 



21. Medullated nerve-bundles in transverse or oblique section. 



*High-power i. e., from three hundred to four hundred diameters. 



