president’s address. 
165 
are so conspicuous in tropical Butterflies. I think the 
specimens of Hypolimnas bolina, which I showed just now, 
are an instance of this unrestrained production of colour. 
Butterflies are comparatively recent denizens of the earth. 
They first appear during the Tertiary geological period, 
and the earliest appearing were probably not brilliantly 
coloured. The same remark applies to the colour of birds, 
so that it would appear that the development of colour in 
nature has been coincident with the appearance of man on 
the scene. 
The colours of flowers have been attributed by the late 
Mr. Grant Allen entirely to insects. In an eloquent para- 
graph he says: “Half the flora of the earth has taken 
the imprint of his likes and dislikes (i.e., the insect’s) and 
his necessities. While man has only tilled a few level plains, 
a few great river valleys, a few peninsular mountain slopes, 
leaving the vast mass of earth untouched by his hand, the 
insect has spread himself over every land in a thousand 
shapes, has made the whole flowering creation subservient 
to his daily wants. His Buttercup, his Dandelion, and his 
Meadowsweet grow thick in every English field. His Thyme 
clothes the hillside ; his Heather purples the bleak, grey 
moorlands. High up among the Alpine heights his gentian 
spreads itself in lakes of blue ; amidst the snows of the 
Himalayas his Rhododendrons gleam with crimson light. 
The insect has thus turned the whole surface of the earth 
into a boundless floral garden ; which supplies him from year 
to year with pollen or honey, and itself in turn gains per- 
petuation by the baits it offers for his allurement.” 
There is doubtless much truth in this statement ; but is it 
the whole truth with respect to the development of colour 
in nature ? 
It can scarcely apply to the brilliant colours of the Butter- 
flies’ wings, and I must say that I think there is some truth 
in Wallace’s view that the existence of colour in nature is 
