UITableView nicht mit Zellen

Ich bin mit Xcode 6, Swift und storyboards erstellen einer IOS-app. Balg ist das, was ich in meiner Datei.swift:

import Foundation

struct December {
    let name : String
}

Dann in meine view-controller habe ich:

import UIKit

class ViewControllerDecember: UITableViewController {

    var december = [December] ()


    override func viewDidLoad() {
        super.viewDidLoad()
        //Do any additional setup after loading the view, typically from a nib.

        self.december = [December(name: "1"), December(name: "2"), December(name: "3"), December(name: "4"), December(name: "5"), December(name: "6"), December(name: "7"), December(name: "8"), December(name: "9"), December(name: "10"), December(name: "11"), December(name: "12"), December(name: "13"), December(name: "14"), December(name: "15"), December(name: "16"), December(name: "17"), December(name: "18"), December(name: "19"), December(name: "20"), December(name: "21"), December(name: "22"), December(name: "23"), December(name: "24"), December(name: "25"), December(name: "26"), December(name: "27"), December(name: "28"), December(name: "29"), December(name: "30"), December(name: "31")]

    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        //Dispose of any resources that can be recreated.
    }

    override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return self.december.count
    }

    override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        let cell = self.tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath) as UITableViewCell

        var de1 : December

        de1 = december[indexPath.row]

        cell.textLabel?.text = de1.name

        return cell


    }
}

Wenn ich die app starte, zeigt er die Tabelle anzeigen, aber keine Daten der Zelle. Was bin ich?