SABAL PALMETTO. 



225 



In Exogens, the bark, wood and pith are clearly defined. 

 In Palmetto, all these are commingled ; no separable bark, 

 no woody layers, no medullary rays. The wood exists in 

 threads or fibers extending lengthwise, traceable from the 

 bases of the petioles down through the soft pith or cellular 

 tissue, at length turning outward and ending in or at the 

 surface where the bark should be. The composition of 

 these wood-fibers or bun- 

 dles may be understood 

 from the cut, which 

 represents the shaving of 

 a Rattan magnified 100 

 diameters. In a single 

 fiber there are annular 

 cells, spiral vessels, dot- 

 ted ducts, and wood-cells, 

 all lying in the cellular 

 tissue, a, a.* 



The Z/eaves are com- 

 paratively few and im- 

 mense, f 7-12 feet in 

 length, including the 

 smooth, channeled peti- 

 ole. The blade is typi- 

 cally fan-shaped (flabelliform),with the border palmately cleft 

 into many segments, in vernation plicate, and parallel-veined. 



Various kinds of vessels in a wood-fiber of 

 Bamboo or Rattan : a, cells of parenchyma ; b, 

 annular cells ; c, spiral vessels ; d, porous duct ; 

 e, wood-cells. 



* Woody stems, whether exogenous or endogenous, are chiefly composed of the 5 

 classes of cells exhibited in the cut. The difference lies in their arrangement. The 

 study of the vegetable cell, in all its varieties, is of great interest and importance, but 

 belongs to a higher department of Botany than is admissible in this work. See Phy- 

 siological Botany, in the Class Book, p. 130. 



t Much has been written of the beauty of the Tropical Palm, decorated with its 

 waving crown. But the Eastern traveler finds a forest of Date Palms, on the banks 

 of the Nile, far less imposing than our own groves of Oak, Birch and Maple. Below 

 is only a vista of naked, monotonous columns, and above a scanty foliage through 

 which the rays of the sun pour in undiminished intensity. 



