Die Embryonalentwicklung der Paradiesschnecke ... - TOBIAS-lib

Kapitel 3
Fig. 2: Histological sections of Pt-exposed embryos and respective sketches explaining
derection of tissue growth. Arrows indicate directional growth of a tissue, X indicates stop
of growth of the respective tissue; black: mantle tissue, red: shell gland, yellow: shell;
A: 3-day-old embryo, transverse section through the visceral sac; B: sketch of Figure 2A,
frontal view; C: 7-day-old embryo, sagittal section; D: sketch of Figure 2C, left lateral view;
E: 9-day-old embryo, transverse section through the visceral sac; F: sketch of Figure 2E,
left lateral view; F: foot; L: lobe; LS: larval stomach; MTE: mantle edge; MTG: mantle
gap; SH: shell; SHG: shell gland; VS: visceral sac.
“sluggish” individuals and directed by the unyielding tissues of mantle edge
and shell gland which form a kind of inflexible ring around the growing
mantle tissue, forcing it to fold inwards (Figures 2E, F). These diverging
forms of development are also illustrated in Figure 3, which shows a control
snail (Figure 3A) with the shell gland in its usual position on the visceral
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