146 Bower.— On the terms ‘ Phyllome' and ‘ Caulome! 
on a phylogenetic view, is little short of a disaster to com- 
parative morphology. Notwithstanding Prof. Sachs 5 disavowal 1 
of any wish to supersede or exclude purely formal comparison, 
the adoption of terms which have already a more or less de- 
finite morphological meaning in a different and still less 
definite physiological sense must result in confusion in the 
minds of students. Here again the regret may be expressed 
that in adopting a new point of view, in itself of the greatest 
value, a correspondingly new series of terms was not intro- 
duced. In morphology the phylogenetic factor is certain to 
become of constantly increasing importance as the effect of 
the hypothesis of evolution takes form in a sounder view of 
the relationship of the main groups of living plants : it is only 
to be expected that, as the sum of known facts increases, mor- 
phological distinctions based upon phylogenetic view will be 
more clearly recognised. The suggestion embodied in this 
paper, to limit the terms ‘ phyllome’ and ‘caulome 5 to the 
sporophore generation, is intended as a step in this direction. 
We should thus arrive at the following classification of vege- 
tative members :• — 
I. Shoot 
II. Root 
( Stem 
( Leaf 
( Phyllidium (oophore). 
( Phyllome (sporophore). 
( Caulidium (oophore). 
I Caulome (sporophore). 
The terms shoot and root, stem and leaf, would thus be used 
in a general sense, being applicable to the corresponding parts 
in both oophore and sporophore indiscriminately; the terms 
phyllome, caulome, and rhizome would, however, be applied 
only to the parts of the sporophore, while the terms phylli- 
dium, caulidium, rhizoid or rhizidium would be reserved for 
the corresponding parts of the oophore. 
1 Lectures, p. 72. 
