welve are merely margin. She will throw them to the
cats, and the foxes, and the weasels, and the snakes, and only keep the
best of the batch. She wants a tree, so she plants a hundred. She
knows that ninety and nine are margin, to be browsed down by cattle,
but she means to make sure of her one. 'The roe of a cod,' Grant Alien
tells me, 'contains nearly ten million eggs; but, if each of those eggs
produced a young fish which arrived at maturity, the whole sea would
immediately become a solid mass of closely packed cod-fish.' But
Nature has no intention of turning her bright blue ocean into a
gigantic box of sardines; she is simply providing herself with a
margin. Linnaeus says that a fly may multiply itself ten thousandfold
in a fortnight. If this increase continued during the three summer
months, he says, one fly at the beginning of summer would produce one
hundred millions of millions of millions before the three months were
over, and the air would be black with the horror. The probability,
however, is that there are never one hundred millions of millions of
millions of flies in the whole world. Nature is not arranging for a
repetition of the plague of Egypt; she is simply gratifying her
appetite for a margin. As Tennyson sings in 'In Memoriam,'

of fifty seeds
She often brings but one to bear.

So I suppose I learned my love of margins from her. At any rate, if
anybody thinks me extravagant, they must quarrel with her and not with
me.

I fancy there's a good deal in it. It is the margin that makes all the
difference. If the work that absolutely must be done occupies every
waking moment of my time, I am a slave; but if it leaves a margin of a
single hour, I am in clover. If my receipts will only just balance my
expenditure, I am living a mere hand-to-mouth existence; but if they
leave me a margin, I jingle the odd coins in my pocket with the pride
of a prince. Mr. Micawber's philosophy comes back to us. 'Annual
income--twenty pounds; annual expenditure--nineteen nineteen six;
result--_happiness_. Annual income--twenty pounds; annual
expenditure--twenty pounds ought and six; result--_misery_.' I believe
that one of the supreme aims of a man's life should be to secure a
margin. Nature does it, and we must copy her. A good life, like a
good book, should have a good margin. I hate books whose pages are so
crowded that you cannot handle them without putting your thumbs on the
type.