File:Keibel Mall 038-039.jpg

Fig. 38. and 39.

Fig. 39 shows the embryo from in front. The amnion has again been removed; ventrally the relatively large yolk sack is seen. Of the embrjonic anlage only the ventrally bent portion, as far back as about the vertex bend, can be seen; but it may be observed that the most anterior portion of the brain anlage is relatively greatly developed. The medullary groove terminates a little behind the cranial end of the medullary aniage, so that the latter shows anteriorly a transverse ridge. Nothing is yet to be seen of the optic pits, the forerunners of the optic vesicles.