How can I dynamically add a controls side by side?

public partial class DemoForm : Form
    {
        private List<PictureBox> pictures;
        private int n = 16;
        public DemoForm()
        {
            InitializeComponent();
            // then form is resing, panel is also resizing and all picture boxes will change their location
            panel.Anchor = AnchorStyles.Top | AnchorStyles.Bottom | AnchorStyles.Left | AnchorStyles.Right;
            numericUpDownMargin.ValueChanged += MarginValueChanged;

            pictures = new List<PictureBox>();
            // adding picture boxes with images
            for(int i=0; i<n; i++)
            {
                var picture = new PictureBox();
                var bmp = new Bitmap(@"path to your image");
                picture.Image = bmp;
                picture.Size = new Size(150,150);
                pictures.Add(picture);
                panel.Controls.Add(picture);
                picture.Visible = true;
            }
        }

        // changing margin of all pictures boxes
        private void MarginValueChanged(object sender, EventArgs e)
        {
            int margin = (int) numericUpDownMargin.Value;
            panel.SuspendLayout();
            foreach (var pictureBox in pictures)
                pictureBox.Margin = new Padding(margin);

            panel.ResumeLayout();
        }
    }