On the limits of the use of the terms ‘Phyllome 5 
and ‘ Caulome/ 
A SUGGESTION, 
BY 
F. O. BOWER, D.Sc., 
Regius Professor of Botany in the University of Glasgow. 
I N the c Practical Course of Instruction in Botany,’ Part II, 
page i, I appended a foot-note to the description of 
the leafy shoot of Polytrichum commune, which runs as 
follows: — ‘Though the terms “stem” and “leaf” are used 
here, it must be distinctly borne in mind that the members 
thus named, being parts of the oophore generation, are not 
homologous with, but at most only analogous to the stem and 
leaf in vascular plants, which are parts of the sporophore 
generation.’ Thinking that this point would be generally 
admitted, no further explanation was given, and it was with 
some surprise that I found this passage objected to by certain 
of my colleagues. Since the point is not universally agreed 
to, and since this passage stands in a somewhat dogmatic 
form in a text-book designed for the use of students, the best 
course will be to state more fully the grounds upon which 
the statement is based. Moreover, there is at present a wave 
of what may be called ‘ morphological scepticism 5 passing over 
the minds of many in this country. Some think the distinc- 
tion of the categories of members is not sufficiently definite; 
others are inclined to deny that distinctions can be drawn at 
all ; thus the present appears to be an opportune time for the 
consideration of the basis on which we rest our distinction of 
the parts of the shoot, viz., stem and leaf, and the limits which 
may, and I think should, now be placed on the application of 
[ Annals of Botany, Vol. I. No. II. November 1887. ] 
