"Native American trades" joke

An old Native American wanted a loan for $500. He approached his local banker. The banker pulled out the loan application, asking, "What are you going to do with the money?"
"Take jewelry to city and sell it," said the old man.
"What have you got for collateral?" queried the banker, going strictly by the book.
"Don't know of collateral."
"Well that's something of value that would cover the cost of the loan. Have you got any vehicles?"
"Yes, I have a 1949 Chevy pickup."
The banker shook his head, "How about livestock?"
"Yes, I have a horse."
"How old is it?"
"I don't know; it has no teeth."
Finally the banker decided to make the $500 loan.
Several weeks later the old man was back in the bank. He pulled out a roll of bills, "Here's the money to pay loan," he said, handing the entire amount including interest.
"What are you going to do with the rest of that money?"
"Put it in my pocket."
"Why don't you deposit it in my bank?" he asked.
"I don't know of deposit."
"Well, you put the money in our bank and we take care of it for you. When you want to use it you can withdraw it."
The old Indian leaned across the desk, looking suspiciously at the banker, and asked, "What you got for collateral?"