Fig. 9. A schematic representation of the LR placement of the adult rudiment in the left and the right half larvae subjected to dissection at three different stages during the period from the early gastrula stage to the two-armed pluteus stage. The left side of the left halves (colored blue in A-C) and the right side of the right halves (colored green in D-F) have been untouched by the dissecting operation. The LR placement of the adult rudiment in the left halves showed distinct patterns according to the stage at which they were dissected. Larvae with a left adult rudiment and larvae with a right adult rudiment were found in about equal proportions after dissection in the early gastrula stage (A). Almost all of the left half larvae formed a right adult rudiment after dissection in the mid-late gastrula stage (B), and the left half larvae formed a left- and a right-adult rudiment after dissection in the prism-pluteus stage (C). Normal LR placement of the adult rudiment was always re-established in the right halves dissected in the early gastrula stage (D), the mid-late gastrula (E) and in the prism-pluteus stage (F).