


viii PREFACE. 
in which repeated subdivision is effected, and most especially the 
distribution of veins scarcely visible to the naked eye, play the 
most important part. To express such facts with the necessary 
. accuracy, the art of a Talbot or a Daguerre was insufficient, nor 
could they be represented pictorially until NATURE-PRINTING was 
brought to its present state of perfection.” 
This art of Nature-Printing, which practice is gradually bringing 
nearer and nearer to a perfect state, represents not only the general 
form of such plants as Ferns, and others, with absolute accuracy, but 
also the veins, and the nature of the surface,—the hairs, and other 
minuti of superficial structure by which they are known, irre- 
spective of the details of their fructification. 
It is true that Nature-Printing has its defects as well as its 
advantages, for it, like the artist, can only represent a portion of the 
whole strueture of the plant; but then its accuracy is perfect as far 
as it goes, and in the case of Ferns, it shows just that which it is 
most desirable to represent for practical purposes, that is, the outline, 
and the venation. If it fails, as it does, to give the details of the 
sori, and their indusia, it accurately gives the general form and 
arrangement even of these parts; and it must not be overlooked that 
such organs are not practically employed in the popular first-sight 
recognition of a Fern, although they are necessary subjects of 
examination in a scientific inquiry. The practised eye recognises 
at a glance the name of a Fern, not by looking to the form of its 
indusium, and the place occupied by the sori, but by its general 
manner of growth, its ramifications, and the form of its leaflets, all 
which peculiarities Nature-Printing shows with unerring truth. And 
this gives it its popular value: it sets forth correctly the first-sight 
appearance a plant bears, and thus, by familiarising the eye with its 
external features, enables even the tyro to recognise the prototype 

