Winton — Anatomy of the Fruit of Cocos nucifera. 269 



angular, with double walls about -005 ram thick and are arranged 

 with some regularity in rows. 



2. Mesocarp. 



(a) Hard ground tissue. — This tissue consists of thick-walled 

 cells which are often tangentially-transversely elongated. In 

 the first few layers the walls are about the same thickness 

 as in the epidermis, without evident pores, but further inward 

 they are more strongly thickened (double walls often \015 mm 

 thick) and conspicuously porous. Still further inward they 

 pass into the parenchyma of the soft ground tissue. 



(b) Bast-fiber bandies. — In the hard ground tissue the bun- 

 dles have no phloem or xylem but are composed entirely of 

 bast-fibers with cell walls often thicker than the lumen. The 

 number of fibers seen in cross section varies from two or three 



Fig. 5. Transverse section of a largo flattened (mesocarp) fiber of the cocoa- 

 nut, ste, stegmata ; /, sheath of bast fibers ; ph. two phloem groups ; x, xylem ; 

 p, parenchyma of ground tissue ; a, rudimentary bundle belonging to small 

 branch, x 90. 



up to a hundred or more. Transitional forms between fibrous 

 and fibro-vascular bundles occur further inward. 



(c) Soft ground tissue. — The thin-walled parenchyma cells of 

 the soft ground tissue are in some parts isodiametric, in other 

 parts longitudinally elongated, and in still other parts trans- 

 versely-tangentially elongated (fig. 8, to). Wherever the 

 brown liquid previously referred to has penetrated the inner 

 layers of the mesocarp, groups of the parenchyma cells here 

 and there, being impregnated with this material, are of a rich 

 brown color and appear thicker-walled than the others (fig. 8, 



