The eschatology is similar to that taught in the similitudes of the Book cf Enoch.
His book is divided into three parts containing visions, commands, similitudes.
First of all write thou my mandates and similitudes; and the rest, as I will show thee, so shalt thou write."
Thus both are hortatory writings, the one argumentative in form, the other prophetic, after the manner of later Old Testament prophets whose messages came in visions and similitudes.
Nature, limited in her resources for adaptation, fashioned so many of these animals in like form that we have learned only recently to distinguish similarities cf analogous habit from the similitudes of real kinship. From whatever order of Mammalia or Reptilia an animal may be derived, prolonged aquatic adaptation will model its outer, and finally its inner, structure according to certain advantageous designs.