276 Winton — Anatomy of the Fruit of Cocos nucifera. 



Most of the ground tissue cells have colorless double walls, 

 from -004 to 4 010 ram thick, with conspicuous (sometimes large) 

 pores, but in the inner layers they often have thinner walls 

 without evident pores and except for their shape bear no 

 resemblance to the other cells. 



As a rule, the cells are empty, but some here and there con- 

 tain a brown substance apparently the same as is contained in 

 the mesocarp and endocarp, which often takes the form of 

 spheres (fig. 10, k), disks, or films with circular openings (v). 



Colorless stone cells (fig. 10, st) are present in the outer 

 layers and contrast strikingly with the deep yellow stone cells 

 of the endocarp. 



Fig, 10. Tangential section of the outer testa of the cocoanut showing the 

 ground tissue of thick-walled porous cells. Most of these are empty, but a few 

 contain brown contents in the form of globules, (k) or films with circular open- 

 ings (v). st, colorless stone cell: sp, spiral trachea, x 300. 



The conspicuous elements of the veins are spiral tracheae, 

 pitted tracheae and elongated cells intermediate between pitted 

 tracheae and the porous cells of the ground tissue, and are not 

 distinguishable from the same elements of the endocarp bun- 

 dles. (See fig. 9, sp, g and/".) 



In breaking away the meat, the separation is through the 

 middle of the veins and the inner layers of the outer testa, 



