176 The Romance of Wild Flowers 
In order that we may clearly understand the nature 
of these Composite flowers, let us revert for a moment 
to the Field Madder (Sherardia), and suppose that 
the little foot-stalks of its separate flowers were all 
suppressed, so that the flowers packed closely together 
stood on the expanded top of the stem with a whorl 
of leaves immediately below them. That would give 
an idea of the way in which Composite flowers pro- 
bably originated. It would seem that there has been 
a tendency among small flowers of various kinds to 
get an advantage out of association. In glancing at 
the umbel-bearers we beheld one direction in which 
this tendency moved; there the tiny, and individually 
obscure, flowers by a loose kind of union became 
conspicuous, so that they attracted many small insects 
who fertilised great numbers of seed-eggs easily, and 
in return got abundance of pollen or nectar with 
little labour. 
In the Guelder Rose (Viburnum opulus) the co- 
operative idea is carried further: the outer row of 
flowers in the cluster being developed to three times the 
size of the others, but containing neither pistil nor 
stamens, the available material being used up to the 
full for the purpose of advertising the flower-cluster 
as a whole. Here, then, we may find an example in 
plant-life of that altruism which Professor Henry 
Drummond believed to be the impelling law in the as- 
cending evolution of the animal kingdom: a number of 
flowers sacrifice their natural function inorder that they 
may thereby aid their sister-flowers to successfully 
complete their mission. This, as we shall see, is not 
the only example of altruism among flowering plants. 
Guelder Rose is not composite-flowered nor a true 
