Scanning electron microscopy of lithium-induced exogastrulae of Xenopus laevis.

Lithium-induced exogastrulae are abnormal embryos which fail to complete gastrulation and do not form normal neural structures. Scanning electron microscopy has been used to compare the surface structure of the ectoderm cells of exogastrulae with that of the ectoderm cells of normal embryos and has shown that the appearance of ciliated cells is delayed in exogastrulae. In addition, the structure of endoderm cells, which remain exposed in these embryos, has been studied.