106 LIVERPOOL BIOLOGICAL SOCIETY. 
substance, protoplasm, but that they are also governed by 
the same laws in their distribution in space and time, and 
have arisen by modification from a common type, we are 
surely justified in employing the term Biology in its wider 
signification only, and in uniting under it the entire range 
of subjects treated of by the sub-sciences of Botany and. 
Zoology. These two sub-sciences are in fact not inde- 
pendent but complementary, the methods employed in 
either are the same, the general conclusions deducible 
from their study are fundamentally alike. 
And yet, until quite recently, Botany has lagged behind 
the sister science, especially in that department wherein 
Zoology has made so great progress, viz. etiology. 
Numerous attempts have been made to arrive at some 
definite conclusions with regard to the path along which 
the animal evolution has passed in its progress from 
the unicellular protozoon to the complex multicellular 
mammal, but few botanists have attempted to unravel the 
genealogical relationships of the numerous tribes of plants. 
Professors Marion and De Saporta* are the most noticeable 
exceptions, and their work has scarcely done more than 
raise a storm of destuctive criticism. If we seek for the 
reason of this feature in botanical history, I think it will 
not be difficult to trace it to the want of that thorough 
comparative morphological knowledge among _ botanists 
which zoologists possessed as a result of the labours of 
the morphological school founded by Cuvier and carried 
on with so great success by his pupils. Not only so, but 
the almost complete ignorance which until quite recently 
prevailed even among the leaders in the science of the life 
histories of the lower plants, and of the meaning of the 
various stages through which they passed, prevented even a 
guess being made as to the signification of the phenomena 
* L’Evolution du Regne Vegétal. 3 vols., Paris, 1881, 
