are explained by Geometry. 13 
illustration: It may be safely affirmed, that the grand dis- 
covery of modern times consists in this, that the mature 
structural elements of orgasms and living beings consist uni- 
versally in cells which are pervious, and perform functions 
represented, so far as is known, by the reasoning above. 
The Transformation of Cells. 
The first fit of life, then, may be said to result in the trans- 
formation, by a variety of causes, of solid spheres, molecules, 
granules, and grains of various sorts, into hollow spheres or 
cells. It is obvious, however, that the course of life cannot 
stop here. During that same phase of the ambient medium 
which developes the cell out of the granule, cells previously ex- 
isting must tend to undergo the same series of changes which 
the granule does, though not so urgently. Thus a cell, how- 
ever pervious its wall, can never expose its interior surface to 
the ambient medium so fully as it exposes its exterior sur- 
face. It can never, in this respect, possess all the advantages 
which are possessed by an open tube or annulus of the same 
extent of surface, or by a filament which has no interior at 
all. Hence, under conditions of existence which are still 
more favourable to the deployment of life than those in which 
primordial cells were generated, we are to expect that such 
cells will be transformed into other forms analogous to those 
which we have traced in reference to solid grains or granules. 
They will also be nearer the region of visibility, if not actu- 
ally within it. These transformations may be thus indicated : 
—(1.) a. Single cells will be transformed into annuli, which 
may be found in suitable positions, as in the interior of more 
persistent cells (see Vegetable Anatomy, Tradescantia, Musa, 
&c.) 6. Each cell in a series may open in opposite regions, 
so as to constitute a short cylinder or bead, and so that a 
line of such two-mouthed cells will constitute a moniliform or 
variously constructed cross-barred cylindrical tube or annular 
duct. (For illustrations of this, also, in abundance, see vege- 
table anatomy, and the current theory as to the genesis of the 
capillaries in animal bodies.) But without opening by larger 
mouths than those on which their permeability depends, cells, 
when the ambient medium is favourable to the deployment of 
life, will tend to depart from the spherical form; for of that 
