Figure 7.

Nucleus measurements in walking leg neuromere 1 of Pseudopallene sp. (late ES 2 – PS 1). The ellipsoid nuclei of the VNE have been measured along their elongated axis. Arithmetic mean is shown, bars represent standard deviation. Small numbers below the values give the number of specimens analysed. Up to the formation of the central invagination (indicated by dashed vertical line), flask-shaped immigrating cells with basally displaced nucleus (dark red squares) have been measured in comparison to cells with apical nucleus (yellow squares). From the formation of the invagination to the hatching of the first post-embryonic stage, the enlarging spindle-shaped cells lining the invagination were measured (dark red circles). The values obtained for late embryonic stages (ES 9–10, stipples outlines) represent most likely an overestimation, since during this developmental period the cells are considerably compressed and distorted due to the pressure exerted by the covering walking leg anlagen [97].