Look at the picture at the top of the next page. I wish I could have given it to you in its proper colours. It looks much nicer like that. Look at it carefully. No other English butterfly has the same pretty curves to its wings, and some of you, I dare say, will know what it is by its shape. But I must tell those who do not know. It is a Brimstone Butterfly, and its colour is bright, bright yellow with an orange spot in the middle of each wing (you can only see one wing in the picture, the other three are hidden behind it; one way to tell a butterfly from a moth is to remember that butterflies' wings close standing up, but nearly all moths' wings close down flat).
It is almost certain that this insect was the first insect to be called "Butter"-fly because of its butter colour. When people began to see that there were other pretty flying things of much the same shape, though of quite different colours, they called them all Butterflies after this first one.
The Red Admiral
A Butterfly of many beautiful colours
So we speak, nowadays, without ever thinking of how funny it really is, of blue butterflies and white butterflies and black butterflies and purple butterflies, and red and yellow and green butterflies—all the colours of the rainbow, in fact.
The Purple Emperor
The most gorgeous Butterfly in England, though not by any means the most beautiful
We would hardly talk of black butter or purple butter, would we?
Some of you will perhaps wonder why the Brimstone Butterfly was the first to be noticed when there are so many others which are just as common.
I think I can tell you.