140 Bower. — On the limits of the use 
wrote as follows : c Lateral axes, leaves, and hairs, arrange 
themselves as regards the time and place of their appearance 
according to their rank. New lateral axes rise from the 
surface of the growing - point earlier, and nearer to its apex 
than the youngest rudiments of leaves.’ Against this is to 
be set the statement of Sachs 1 : ‘ I constantly find in vege- 
tative shoots and many inflorescences of Phanerogams young 
leaves above the youngest axillary buds.’ This question 
has also been treated at length by Warming 2 , who has shown 
that though in the vegetative shoot the leaf as a rule precedes 
the axillary bud, in many inflorescences the bud may precede 
its subtending leaf, or the subtending leaf may be entirely 
absent. Again, Goebel’s observations 3 on ‘ dorsiventral in- 
florescences ’ and on ‘intercalary growing-points’ indicate, 
together with the above, that relative time and place of 
origin will not serve as a safe criterion of distinction of axis 
and leaf. In fact we arrive at the conclusion put forward 
by various writers, that all the above-mentioned characters 
have only a relative value as applied to the distinction of 
axis and leaf, all of them being limited by exceptions : in 
other words, organic nature is not limited by strict rules, 
and a perfectly natural system of morphology of the shoot 
cannot be based on narrow definitions. 
The difficulty of defining and distinguishing stem and leaf 
is in itself to be regarded as a strong justification of their 
designation under the common term ‘ shoot,’ which Sachs 
has adopted in his Lectures as the correlative of the ‘ root.’ 
Accepting this idea of the shoot as a whole, one is apt to 
doubt, in view of the difficulty of their definition, whether 
there be any essential difference between axis and leaf; 
and this question is closely connected with the idea of a 
possible ‘ terminal leaf : ’ if there be any recognisable difference 
then the terminal leaf is at least a possibility. Now Sachs’ 
1 Textbook, 1st English edition, p. 154, footnote. 
2 Forgreningsforhold, pp. viii-xi. 
3 Ueber die Verzweigung dorsiventrale Sprosse. Also Vergl. Entwickelungs- 
geschichte. 
