302 AQUATIC MICROSCOPY FOR BEGINNERS. 



• 



trouble that their preparation seems to demand. The 

 ribbons should be examined in water or glycerine. A 

 high power will often be required to show the teeth 

 well. 



13. The delicate epidermis from the leaves of 

 plants may be obtained at any time in an unlimited 

 supply and variety — in summer from the wild plants, 

 in winter from those cultivated in the house. The ■ 

 cells forming this thin and usually colorless membrane 

 vary in form and size in the leaves of every plant, and 

 the stomata or breathing pores also present very 

 varied shapes, being most abundant on the under sur- 

 face. The cells are usually empty; occasionally, 

 however, they contain some chlorophyl grains and 

 sometimes diffused coloring matter. The cuticle can 

 be sliced off with a sharp razor, but a better way is to 

 strip it off by tearing the leaf in a manner easily ac- 

 quired but hardly describable. The piece obtained 

 may be small, but it will probably be sufficient for ex- 

 amination. All cuticles should be examined in water. 



14. Deutzia scabra, a handsome shrub now very 

 common in cultivation, has Ifeaves of special interest 

 on account of the beautiful stellate hairs studding the 

 surface. The cuticle may be removed and viewed as a 

 transparent object, or a portion of the leaf may be ex- 

 amined by reflected light. By either method the ob- 

 server will be pleased and interested. These stellate 

 hairs are hard, brittle, and glass-like, and are occasion- 

 ally so well developed that they are visible to the naked 

 eye as minute glistening stars. Under a good pocket- 

 lens they are at all times apparent. They are most 

 abundant on the upper surface. 



15. Oleander Leaves (NMum Olednder, a shrub 



