[119] But there is one kind of creation, which is a sort of conducting and travelling from that which does not exist to existence. This is the one which plants, and animals do of necessity use; and there is another kind, which is a transition and change from a better genus to a worse species, which Moses mentions when he says, "These are the generations of Jacob; Joseph when he was seventeen years of age, was keeping the sheep with his brethren, being a youth with the sons of Billah, and with the sons of Zilpah, his father’s wives." [58]