166 RELATIONSHIPS OF THE INDEFINITE INFLORESCENCES, 
Darwin and others to be adaptations for cross-fertilization, is an 
additional argument in favour of the view that inflorescences form 
one of the simplest cases of adaptation to environment. 
OBJECTIONS TO THESE RELATIONSHIPS. 
I pass now to a brief consideration of the more obvious objections 
which may be raised to the sequence of these relationships. As has 
been already stated, most authors regard all indefinite inflorescences 
as modifications of the raceme. Thus in Le Maout and Decaisne’s 
System of Botany the raceme is taken as the type, and the other 
forms derived from it. The umbel, for instance, is regarded as a 
r 
with vertically thickened and dilated primary axis. In the case of 
simple and compound umbels, since the outer flowers open first, 
‘we may conclude that the umbel is a compressed raceme.”’* 
In a recent paper on Inflorescences by M. Hy,t the following 
table is given :— 
Principat VaRIATIONS OF THE RacEME. 
Peduncles distinct. Peduneles short. 
Elongated. Raceme. | Spike. 
_ nomen mse Very short. Umbel. | Capitulum. 
é raceme we must have direct contraction of the 
primary axis, just as one sees illustrated by the shutting up of an 
extended telescope. ‘‘Telescoping,” in fact, would take place. 
Such phenomena are extremely rare in the vegetable kingdom, and 
I venture to think that the view put forward by the theory of 
internodes, namely, that the elongation of certain internodes never 
takes place at all, is preferable to imagining that the same internodes 
were at one time fully expanded, and afterwards contracted, as they 
must have done if the umbel was formed from the raceme. It is 
hardly possible, I think, to interpret Le Maout and Decaisne’s 
words to mean non-development in the first place. If, however, 
they are to be regarded in that light, then we have at once the 
theory of internodes, and the derivation of all these forms from the 
inflorescence from raceme also ves the development of 
simpler from more highly organized forms, and this, as has already 
b ted out, is far from natu There is also evidence that 
the chain of relationships is in many cases closer than any that can 
be imagined, if these forms are all derived from a raceme. 
* Hooker, ibid. p. 38. 
t M. F. Hy, Rev. Gén. de Bot. vols. vi. & vii., 1894-5, p. 391, &c. 
