I described to her the brain, the pineal organ in Anguis, Sphenodon's pineal eye, etc.
This pineal eye has been compared in structure to the eye of Ascidians.
Fig. 141 represents a section through the head near the pineal eye.
A sensory structure capable of light reception, appearing as a spot on the top of the head in lampreys, hagfish, amphibians, and some reptiles, especially the tuatara. Pineal eyes can contain a rudimentary cornea, lens, cone cells, and retina, and are thought to be sensitive to light and dark but not to be able to form images.