1S92.J NEW-YORK MICROSCOPICAL SOCIETY. 109 



more clearly discerned where, at the edges, the section thins 

 away almost infinitesimally. The sections were cleared of cell- 

 contents by boiling in a dilute solution of caustic soda, stained 

 with hsematoxylin, and mounted in balsam. 



Figs. 6 and 7 represent a continuous narrow strip of the trans- 

 verse section, running from a, through b and c, to d — from 

 the brown seed coats to the soft tissue of the cleft. The cells 

 of the seed coats will be mentioned more conveniently under a 

 consideration of the longitudinal-tangential section. Just within 

 the seed coats at a is a structure of peculiar cells, bounding the 

 entire circumference of the endosperm, which, from their form, 

 may be termed palisade cells. They are uniformly thickened 

 cells with smooth walls. They vary in length. Some of them 

 are nearly cubical. But the majority of them are hexagonal 

 prisms, with a nearly flat outer end, next the seed coats, and an 

 obliquely truncated end, within, toward the endospeim. 



Immediately succeeding these last lie the "spindle cells," 

 slightly overlapping each other, and with their long diameters all 

 directed toward the long axis of the stone. In the figures the 

 clear spaces represent the interior of the cells, and the oblique 

 shading represents the cut surface of the adjoining thickened 

 cell walls. In a general view of the section, next after the strik- 

 ing appearance of the cell cavities, the attention is arrested by 

 the appearance of an immense number of little circles irregularly 

 scattered through the structure. These circles are the sections 

 of the deep and remarkably uniform pores, extending from the 

 interior of the cells, through the thickened cell walls, to the middle 

 lamella between two adjoining cells. This explanation is easily 

 demonstrated by a view of the uncleared cell contents in some 

 of the thicker portions of the section. The cell contents take 

 the stain more deeply than the cell walls, and occasionally, where 

 a cell has not been cut open by the section, the soda treatment 

 has failed to expel the contents, and these contents then form a 

 distinct dark-colored cast of the cell cavity. This cast is some- 

 what cigar-shaped and studded with numerous prominent pro- 

 jections, like stout projecting nail heads. These nail heads are 

 evidently the casts of the cell contents filling the pores. And 

 the little circles abounding through the structure are the sections 

 of these pores in various positions, now emptied of their contents. 



