"I beg your pardon," said Ian, "but if you know no more about the
rich than you do about the fish, I can hardly take your testimony.
The fish are the most carnivorous creatures in the world."

"Do they eat each other?"

"Hardly that. Only the cats of Kilkenny can do that."

"I used a common phrase!"

"You did, and I am rude: the phrase must bear the blame for both of
us. But the fish are even cannibals--eating the young of their own
species! They are the most destructive of creatures to other lives."

"I suppose," said Mercy, "to make one kind of creature live on
another kind, is the way to get the greatest good for the greatest
number!"

"That doctrine, which seems to content most people, appears to me a
poverty-stricken and selfish one. I can admit nothing but the
greatest good to every individual creature."

"Don't you think we had better be going, Mercy? It has got quite
cold; I am afraid it will rain," said Christina, drawing her cloak
round her with a little shiver.

"I am ready," answered Mercy.

The brothers looked at each other. They had come out to spend the
day together, but they could not leave the ladies to go home alone;