IV] BUDS AND BRANCHING 71 



nutriment from the leaf before it reaches the stem, and can at the same 

 time grow directly outwards from the parent plant, maybe held as conducing 

 to the perpetuation of buds of this type. 



Other positions, either laterally upon /viii ^JT'^ 



the leaf-base or upon the axis slightly yf A 



removed from the leaf-insertion, are also V ' • 



frequent, and especially upon dorsi- » > ''vii 



ventral rhizomes. But such positions /vi P / 



are not so fixed or constant as are the Jr" / i; 



buds on the abaxial side of the leaf- m 4<V " 



base. § " j C 



Those buds which appear to be ^'^^ \ « j>%z: ' '^^'^ 



formed early and in definite positions ... (iT"* 1' #7 /iii 



upon the leaf-bases of Angiopteris may '^ '^'^^Lm 



here also be noted (63). They arise at the yf '' 



corners where the margins of each of ^" * 



the stipules pass over into the leaf-base, .. - \ 



and there are accordingly four of them ^"*'~'*^ '—«i|^ 



on each leaf-base. They are seated, as ^^^4 «^ i 



in Helviinthostachys, each at the base ^^ 



of a narrow canal. The buds remain 



dormant till the leaf-bases separate with Fig. 65. Drawing by Dr j. M. Thompson of a 



age from the trunk: after which event ^"^^^om^^iChe^ropleuriabicusph 



*> _ with the superhcial han-s removed, so as to 



they may grow on, each forming a new expose the successive leaf-bases, which are 



, , T-1 , --1 ...I- 1 1 r numbered /i to /viii, and the lateral axes 



plant. The analogy with the buds of which spring from their bases, numbered «xi 



Hehninthostachys is very striking except to ax iv. But the leaves iii, vi, vii, viii have 



. ... .,, no associated axes. The leaf-arrangement is 



that their position is not axillary, and alternate, and the climbing shoot is seen from 



their number is greater. ^^^ ^"^^ f^<='"g ^'^'^y f-'O"^ ^'^'^ support. ( x 2.) 



(IV) Buds are also formed at various points on the expanded lamina, 

 but naturally these are later in their origin than those above described. 

 They may be found related apparently either to the lower or to the upper 

 surface, though in some cases their origin appears to be in the first in- 

 stance marginal. The former is the case in Asplenhim bulbiferwri, the latter 

 in Asplenium viviparum, Diplaziinn celtidifolimn, and Dennstaedtia rubigi- 

 nosa: and this is the more common type. The buds frequently appear close 

 to the bases of the pinnae, as in Woodwardia radicans, and Cystopteris bid- 

 bifera (Fig. 66): but often their position is less definite than this. In certain 

 cases their origin has been traced to single superficial cells, which awake 

 relatively late to renewed activity of growth and division. Being seated on 

 a narrow base these buds are easily detached, and provide a ready means 

 of vegetative propagation, as seen in various species o{ Asplenium. In certain 

 cases the production of such sporophytic buds may be definitely related to 



