144 
Bower . — On the limits of the use 
and especially on behalf of students, that this conclusion 
should appear on the face of our terminology ; the enclosure of 
the words ‘leaf’ and ‘ stem ’ in inverted commas, when applied 
to the oophore generation, is but an impotent distinguishing 
mark. I would therefore propose that the terms phyllome and 
caulome be reserved for those parts of the sporophore genera- 
tion which are usually so called, thus retaining those terms in 
their original sense ; while the terms c phyllidium 5 and ‘ cauli- 
dium ’ might serve for the analogous developments in the 
oophore generation. Such a distinction of terms has been 
habitual in regard to the roots, the term * root ’ (rhizome), 
in the sense adopted by Sachs in his Text-book, being applied 
to the true root of the sporophore, while the terms ‘ rhizoid,’ 
‘ rhizine ’ (or perhaps better ‘ rhizidium ’), express the analo- 
gous and functionally similar parts in the oophore 1 . 
I am aware that objection will be raised to this proposal on 
the ground that it will be impossible to distinguish all parallel 
or morphologically analogous developments by distinct terms : 
thus, if we admit that heterospory has arisen at more than one 
point in the Vascular Cryptogams, it is at present unnecessary 
to distinguish the different sporangia in heterosporous Ferns, 
fossil Equisetums, and Lycopods by distinct terms : this is 
obvious. But it is, as far as I can see, no objection to the 
adoption of distinctive terms in what is the most prominent 
case of parallel development in the whole series of plants, or 
in other cases also where such a course would be conducive to 
clearness 2 . 
1 It is in connection with the term ‘ rhizoid ’ that Professor Sachs has most con- 
spicuously thrown overboard a distinction of terms which conveys the idea of want 
of homology in functionally similar parts. - The avowed object of removing the 
cause of that ‘ prejudice against descriptive Botany still frequently existing even in 
scientific circles’ can hardly be accepted as sufficient to justify the sacrifice of 
clearness of conception. Compare Lectures, p. 35. 
2 There can be few morphologists who have not felt the impropriety of desig- 
nating by the same term the true leaf or phyllome of the higher plants and such 
members as the so-called leaves of Nitella or Caulerpa , the limited lateral branches 
of Florideae, the amphigastria of Marchantia , none of which can have been lineally 
connected with the true leaf of the sporophore : such members would fall under 
the term phyllidia, and thus be distinguished from the true sporophoric phyllome. 
It is true the analogies are at times extremely close, as that of the phyllidium of 
