The 3-dimensional image to the left shows a line indicating a coronal section through the diencephalon and telencephalon. To the right you can see a diagram representing that coronal slice. Click the link to the right now to animate that animation. The cerebral hemispheres grow laterally from the cranial end of the neural tube.

As you can see, the fluid filled neural canal also expands bilaterally within the growing hemispheres. The color coding of the subdivisions of the neural tube are now visible again as a reminder. After we remove the color coding, we show continued growth of the neural tube. Making the 3-dimensional image see through provides us a reminder of the shape and position of the neural canal and the alar and basal columns.