Slide showing diagrammatic drawing of an unidentified embyro 'after strong constriction, corresponding to Fig. 13'. Slide shows diagrammatic drawing of an unidentified embyro 'after strong constriction, corresponding to Fig. 13'. Fig. 13 not found so far. Left part of embryo has a slight coloured tint. Title below image reads: 'Fig. 15. The same, after strong constriction, corresponding to Fig. 13. The nucleus which lies nearest to the plasmic bridge has sent a descendant into the other half; the latter is about to be cut off by a furrow. (After Fankhauser, 1930a.)' Late 19th to early 20th century