Activate the search field in ios 9 mail?

I feel like an idiot because I can't figure this out and I'm sure it's easy-peasy, but since updating to ios 9 on my iPad Air 2, the search field within the email app has disappeared. I have scoured Mail Settings and everywhere else I could think of but I can't find how to make it appear. I know I can use Spotlight but I want the search that's dedicated to the Mail app. Please help me out.