RELATIONSHIPS OF THE INDEFINITE INFLORESCENCES. 165 
INFLORESCENCES AS ADAPTATIONS. 
The greatest support which can be brought forward in favour of 
the relationships suggested in this paper may perhaps be gained from 
a consideration of the question why a particular form of inflorescence 
ssessed b h 
ficance, and in light of modern research it can hardly be ioebied 
that the explanation is to be found in the study of adaptation to 
environment. In the last few years great, perhaps the greatest, 
progress in vegetable biology has been made along these lines. 
This subject foe engaged the attention of many of the greatest 
aT botanists, who have in the course of their magnificent 
resoarohes amy expanded the principles which we owe in the first 
place to Dar Much of this work has a direct bearing on the 
aii se Hp by je ao of internodes 
In many cases one of the chief differences noticed in plants 
under altered conditions is ne gevaitae ion or contraction of the 
internodes. Thus, among the phenomena of etiolation the elongation 
of the internodes is a fairly constant feature, and has been shown by 
Godlewski* and by Mr. F'. Darwin} to be a form of adaptation to 
circumstances. 
onnier, { 3 his researches on the effect of continual illumi- 
nation on plants, and particularly in his observations on the 
anatomical fm orphological differences between species which 
in alpine and arctic situations, has shown that one of 
the chief effects of such continual illumination is a contraction or 
basis of the above relationships, is therefore an extremely likely 
phenomenon under processes of altered conditions. There can be 
no doubt that plants do constantly change their bas and in doing 
so must come face to face with altered conditions. In the Alps, for 
instance, many species essentially ig d in origin ascend even to 
high alpine places, where it is obvious that a very serious change 
iti i ants In 
of conditions ts’ es aco takes 
ritish flora there are many instances of species or Pep te i 
plants found along our coasts which differ more or les edl 
nature of the habitat of the plant. If this is the case, there is no 
reason why the inflorescences of a plant should be less liable to 
modification than any other detail; on the contrary, we learn from 
Bonnier’s researches that internodal changes are most marked 
under altered conditions. The extreme modification sa the 
flowers themselves undergo, and which have been shown by 
* Godlewski, Biolog. Centralblatt, Oct. 15, 1889, &e. 
F. Darwin, Journ. R. Hort. Soc., March, 1896. 
t Bonnier, Rev. Gén. de Botan. vols, vi. & yii., 1894-5, 
