Don produced the letter, and David took it with a very unsteady hand.  A hundred and fifty dollars was a fortune in his eyes, a larger one too than he had hoped to earn for some years to come.  He opened the letter and one glance at it showed him that the money was his, if he could only capture the required number of birds.  They were to be trapped at once, the sooner the better, put into boxes, which were to be marked C. O. D. and forwarded, charges paid, to the address at the bottom of the letter.

“Cod,” repeated David, whose opportunities for learning how business was transacted had been very limited, “does he mean codfish?” Don and Bert laughed heartily.

“No,” said the former, as soon as he could speak.  “C.  O. D. means ‘collect on delivery.’”

“O,” said David, in a tone of voice which showed that he did not yet fully understand.

“It is nothing to be ashamed of,” said Bert; “we didn’t know what the letters meant until father told us.”

“That’s so,” said Don; “how is a fellow to know a thing he has never had a chance to learn?  Now when the birds are caught, you put so many of them in a box and on each box you mark the value of its contents.  You send a notice of shipment to the man, and he will know when to look for the birds.  When they arrive he pays the amount of your bill to the express agent, and the agent forwards it to you.  You run no risk whatever, for the man can’t get the quails until your bill is paid.”

“Now I’ll tell you what we’ll do,” said Bert, who saw by the expression on David’s face that his brother had not made matters much clearer by his explanation, “you go to work and catch the quails, and when you have made up the required number, we’ll help you ship them off.”

“That’s the idea,” said Don.  “We’ll do anything we can for you.”

“Thank you,” answered David, who felt as if a tremendous responsibility had been removed from his shoulders.

“I’ll write to the man to-day, informing him that you will go to work at once,” added Don.  “I don’t suppose you could tell, even within a week or two, of the time it will take you to fill the order, could you?”

“I shouldn’t like to make a guess,” said David.  “The birds rove around so that a fellow can’t tell anything about them.  They are plenty now, but next week there may not be half a dozen flocks to be found.”

“Then I will write to him that the best you can say is, that you will lose no time.  How does the pointer come on?”

“Finely,” said David.  “He works better than half the old dogs now.  He’s smart, I tell you.”

“He takes after his owner, you see.  I hope to get firmly on my feet next week, and if I do, I want to try him.  Good-by.”

“Now, there are two friends worth having,” thought David, gazing almost lovingly after the brothers, as they rode away.  “I don’t wonder that everybody likes them.  A hundred and fifty dollars!  Whew! won’t mother have some nice, warm clothes this winter, and won’t she have everything else she wants, too?”