Rabbi Mana said: Such creatures which have been created from the earth increase and multiply on the earth, and such which have been brought forth from the water increase and multiply in the water, except all kinds of winged birds, for their creation was || from the water, yet they increase and multiply on the earth, as it is said, "And let the fowl multiply in the earth" (Gen. 1:22). Such as were brought forth from the water increase and multiply by the egg; and such as were created from the earth increase and multiply by fœtus (i.e. living offspring).