[Round nucleus of Emys orbicularis tortoises during ontogenesis (light and electron microscopy findings)]

It has been demonstrated that in the tortoise after hatching the round nucleus and its neurons are rather small, neuronal density is high. Neurons contain a large amount of free ribosomes, Nissl bodies are absent. Single axodendritic synapses are predominant, polysynaptic complexes of the glomerula type are absent. These data indicate that in newborn tortoises the round nucleus does not attain definitive form, differentiation of its main elements proceeding after hatching.