After the Doctor had written his first letter by Swallow Mail to the Cats'-Meat-Man he began to think of all the other people to whom he had neglected to write for years and years. And very soon every spare moment he had was filled in writing to friends and acquaintances everywhere.  
And then, of course, there were the letters he sent to and received from birds and animals all over the world. First he wrote to the various bird leaders who were in charge of the branch offices at Horn, Thibet, Tahiti, Kashmir, Christmas Island, Greenland and Puddleby-on-the-Marsh. To them he gave careful instructions how the branch post offices were to be run—always insisting on strict politeness from the post office clerks; and he answered all the questions that the branch postmasters wrote asking for guidance.
 
And he sent letters to various fellow whom he knew in different countries and gave them a whole lot of information about the yearly flights or of birds. Because, of course, in the bird mail business he learned a great deal on that subject that had never been known to naturalists before.
 
Outside the post office he had a notice board set up on which were posted the Outgoing and Incoming Mails. The notices would read something like this:
 
Next Wednesday, July 18, the Red-Winged will leave this office for Denmark and points on the Skager Rack. Post your mail early, please. All letters should bear a four-penny stamp. Small packages will also be carried on this flight for Morocco, Portugal and the Channel Islands.
 
Whenever a new flight of birds were expected at No-Man's-Land the Doctor always had a big supply of food of their particular kind got ready for their arrival before-hand. He had at the big meeting with the leaders put down in his notebook the dates of all the yearly flights of the different kinds of birds, where they started from and where they went to. And this notebook was kept with great care.
 
One day Speedy was sitting on top of the weighing scales while the Doctor was sorting a large pile of outgoing letters. Suddenly the Skimmer cried out:
 
"Great heavens, Doctor, I've gained an ounce! I'll never be able to fly in the races again. Look, it says four and a half ounces!"
 
 
 
"No, Speedy," said the Doctor. "See, you have an ounce weight on the pan as well as yourself. That makes you only three and a half ounces."
 
"Oh," said the Skimmer, "is that the trouble? I was never good at arithmetic. What a relief! Thank goodness, I haven't gained!"
 
"Listen, Speedy," said the Doctor, "in this of mail we have a lot of letters for Panama. What mails have we got going out to-morrow?"
 
"I'm not sure," said Speedy. "I'll go and look at the notice board. I think it's the Golden Jays.... Yes," he said, coming back in a moment, "that's right, the Golden Jays to-morrow, Tuesday, the 15th, weather permitting."
 
"Where are they bound for, Speedy?" asked the Doctor. "My notebook's in the safe."
 
"From Dahomey to Venezuela," said Speedy, raising his right foot to a yawn.
 
"Good," said John Dolittle. "Then they can take these Panama letters for me. It won't be much out of their way. What do Golden Jays eat?"
 
"They are very fond of ," said Speedy.
 
"All right," said the Doctor. "Please tell Gub-Gub for me to go across to the island and get the wild boars to gather up a couple of sacks of acorns. I want all the birds who work for us to have a good feed before they leave the Main Office for their flights."
 
The next morning when the Doctor woke up he heard a tremendous all around the post office and he knew that the Golden Jays had arrived overnight. And after he had dressed and come out on to the , there, sure enough, they were—myriads of very handsome gold and black birds, everywhere, gossiping away at a great rate and gobbling up the acorns laid out for them in bushels.
 
The leader, who already knew the Doctor, of course, came forward to get orders and to see how much mail there was to be carried.
 
After everything had been arranged and the leader had he need expect no or bad weather for the next twenty-four hours, he gave a command. Then all the birds rose in the air to fly away—whistling farewell to Postmaster General Dolittle and the Head Office.
 
"Oh, by the way, Doctor," said the leader, turning back a moment, "did you ever hear of a man called Christopher Columbus?"
 
"Oh, surely," said the Doctor. "He discovered America in 1492."
 
"Well, I just wanted to tell you," said the Jay, "that if it hadn't been for an ancestor of mine............