External appearances of hydromyelic and normal embryos

(A) Frontal view of an embryo with a hydromyelic change at the level of lower limb buds (arrowhead).
(B) A closer view of the caudal part of the same embryo, showing the dilated neural tube.
(C) The caudal part of a normal embryo at the same stage of development.
(D, E) Caudal views of embryos with the dilated caudal neural tube at a slightly later stage of development.
(F) The caudal part of a normal embryo in the same stage of development.