3 4I of the greatest width of the neural plate of Amblystmima did not prevent the formation of two eyes (figs. zoz). In the majority of cases (9 out of iL) brain and eyes were regulated to form a harmonious whole. This has been confirmed by Mangold ('31) who found that after the removal of a median strip as broad as

2 the greatest breadth of the neural plate, or quite to the midline and back as far as the broadest portion of the neural plate. This is in accordance with the findings of Wachs ('zo), who demonstrated, further, that a small eye formed after the removal of a lateral segment of the medullary plate may subsequently attain normal size and structure. A similar restitution was also noted by Mangold ('3I). When twothirds of the anterior end of the neural plate are removed, the remaining lateral third gives rise to an eye which may equal the normal proportions (Adelmann,'zga).