Hadi

With regard to serpents or snakes, the viper is externally
viviparous, having been previously oviparous internally. The egg, as
with the egg of fishes, is uniform in colour and soft-skinned. The
young serpent grows on the surface of the egg, and, like the young
of fishes, has no shell-like envelopment. The young of the viper is
born inside a membrane that bursts from off the young creature in
three days; and at times the young viper eats its way out from the
inside of the egg. The mother viper brings forth all its young in
one day, twenty in number, and one at a time. The other serpents are
externally oviparous, and their eggs are strung on to one another like
a lady's necklace; after the dam has laid her eggs in the ground she
broods over them, and hatches the eggs in the following year.