259 
PLANTS KNOWN BY THEIR POLLEN-ORAINS 
AND OTHER CELLS. 
By GEORGE GULLIVER, F.R.S. 
H ad the eminent botanical artist, Bauer, lived to extend 
that beautiful set of drawings, of which specimens are 
preserved in the British Museum, the diagnostic value of the 
Pollen-grains and other cells must have been earlier forced on 
the acceptance of botanists. But, however admirable may be 
the progress of systematic botany since his time, a luxuriant 
though uncultivated field still lies neglected in an important 
department ; and this is the cell-biography of species. Nor, 
until the affinities and contrasts of the most essential structural 
elements of plants have been as completely shown as our present 
improved means of research will allow, can we hope to attain 
the best skill in our power for a natural classification of the 
vegetable kingdom. 
The most essential structural element truly ; for every botanist 
now admits that this, in one form or other, is a cell. To the 
history, then, of this element we may look with the hope of 
deriving valuable help in the formation of truly natural cha- 
racters for the arrangement of plants, and this through an 
extension of our knowledge of their structure and physiology ; 
and, as mentioned in the 571st page of the fourth volume of 
this Journal, of animals also, a remarkable example of which 
may be seen in the form, pointed at both ends, of the red blood- 
corpuscles of the pike, a cell -character in which this fish plainly 
differs from other and congenerous species. 
As regards the vegetable world, good use no doubt has been 
already made of the pollen and other cells in the classification 
of large sections, and of the spores and other cells for the 
characters of smaller groups, and even species, of some of the 
lower orders, such as the mosses and their allies. But we have 
only to refer to our best systematic arrangements and floras of 
the Phanerogamia to discover a lamentable deficiency in the 
present point of view. The worthy authors seem tacitly to 
accept Schleiden’s assertion, that systematic botany has little 
