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Anatomy of Spartina Townsendn. 
coating in preventing water from adhering to, and wetting the upper 
surface. Their efficiency may be gauged by the fact that leaves, sub- 
merged in the laboratory for more than twenty-four hours, were quite 
Fig. i. i. Epidermis of upper surface of leaf-blade, showing simple papillae ( pa and pa ) ; 
hydathode (Jiy ) ; and special stomata ( st ). 2. Epidermis of abaxial surface with ordinary stoma; 
pits (/) ; and hair (h). 3. Epidermis of abaxial surface of leaf-sheath immediately below the 
articulation : silica-cell (si) ; saddle-cell (sa). 4. Epidermis of articulation region, showing thick- 
walled pitted cells with very wavy outline. 5. Radial longitudinal section through 3 : nucleus 
beneath silica body (11). 6. Enlarged surface view of the two types of short cells. 
dry when taken out and shaken slightly. The normal period of natural 
submersion rarely exceeds a few hours. 
The number of variations in the epidermis of different portions of the 
plant are merely changes rung on an essentially simple ground-plan, 
either of long cells alone, or more often of long cells alternating with 
