FIGURE 2.212. SECTION OF AN AMPHIOXUS-LARVA.

FIGURE 2.213. DIAGRAM OF PRECEDING.

FIGURE 2.214. SECTION OF A YOUNG AMPHIOXUS.

FIGURE 2.215. DIAGRAM OF A YOUNG AMPHIOXUS.

FIGURE 2.216. TRANSVERSE SECTION OF LANCELET.

FIGURE 2.217. SECTION THROUGH THE MIDDLE OF THE LANCELET.

FIGURE 2.218. SECTION OF A PRIMITIVE-FISH EMBRYO.

FIGURE 2.219. SECTION OF THE HEAD OF THE LANCELET.

FIGURES 2.220 AND 2.221. ORGANISATION OF AN ASCIDIA.

FIGURES 2.222 TO 2.224. SECTIONS OF YOUNG AMPHIOXUS-LARVAE.

FIGURE 2.225. AN APPENDICARIA.

FIGURE 2.226. Chroococcus minor.

FIGURE 2.227. Aphanocapsa primordialis.

FIGURE 2.228. PROTAMOEBA.

FIGURE 2.229. ORIGINAL OVUM-CLEAVAGE.