THE SHAPE OF CELLS. 



541 



a 



/ 



FiGURE 1. a, a rhomboidal dodecahedron, and b, an elongated form of the 

 same, c, a truncate dodecahedron, and d, a flattened form of the same 

 (a-d, after Kieser). e-i, an orthic tetrakaidecahedron shown in its several 

 aspects. 



des vegetaux, Paris, 1824, p. 49) succeeded in isolating the cells of pith by- 

 boiling them in nitric acid, and thus demonstrated that they are closed vesicles, 

 independent though agglomerated. But of their shape he says merely, — 

 "Their original form is globular; it is from the equality of the compression to 

 which they are subjected in all directions that they often assume a sym- 

 metrical polyhedral form." It may readily be surmised why he did not 

 describe the polyhedra in greater detail. 



