Master Detail Page XAML only displays Detail Information.

I have the following XAML, which is slightly modified from an example found here: http://stackoverflow.com/questions/26887374/xamarin-create-masterdetailpage-with-multiple-detail-view-using-xaml

    <?xml version="1.0" encoding="UTF-8"?>
    <MasterDetailPage xmlns="http://xamarin.com/schemas/2014/forms"
                      xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
                      xmlns:local="clr-namespace:TimesheetList;assembly=TimesheetList"
                      x:Class="TimesheetEntry.TimesheetList" Title="Timesheet List" >
        <MasterDetailPage.Master>
            <ContentPage Title="Master">
                <Label Text="Test Master" VerticalOptions="Center" HorizontalOptions="Center" />
            </ContentPage>
        </MasterDetailPage.Master>

        <MasterDetailPage.Detail>
            <ContentPage>
                <Label Text="Hello World" VerticalOptions="Center" HorizontalOptions="Center" />
            </ContentPage>
        </MasterDetailPage.Detail>
    </MasterDetailPage>

With the following C#:

    public partial class TimesheetList : MasterDetailPage
    {
        public TimesheetList ()
        {
            InitializeComponent ();
        }
    }

I only see the Detail label and not the Master label. I've most likely missed something small that's not allowing it to display the detail information. Perhaps I need to add some additional C#?