Localization of the Neural Inductor and Tail Mesoderm in a Frog Egg ( Hyla regilla ) ∗

Conclusions

1. In the early gastrula of the anuran Hyla regilla the inductor of the neural plate is localized approximately in the dorsal lip region of the mesodermal band, that is, it extends about 45° on either side of the dorsal mid-line. 2. The tail-forming potencies are localized in the lateral and ventro-lateral regions of the mesoderm, with the higher percentage of tails developing from the ventro-lateral regions after implantation. The dorsal and the ventral lip mesoderm do not form tails after implantation. 3. The present results show that the anuran Hyla has distinct differences in the localization of certain developmental capacities as compared to the eggs of urodeles. Both the neural inductor and the tail mesoderm have a more limited meridional extent in Hyla.