Wire sample problem?

Using Arduino Networking, Protocols, and Devices
1

I was just reading this tutorial, and making research about it and saw this schematic.

There is missing two pull ups resistors on A5 and A4, right?

2

Two Arduinos close together may well work as illustrated, as the Wire library enables internal pull-ups. Better would be to have 4.7K pull-ups on both SDA and SCL.