H.P. Blavatsky's Rounds or stages of cosmic evolution are concerned more with the evolution of man (in his original etheric form) rather than with the cosmos as such. Ironically, her Cosmogony (theory of the origin of the cosmos) is in this sense an Anthropogony (theory of the origin of man), whilst Rudolph Steiner's Anthroposophy ("Wisdom about man") is more often also a Cosmogony.
Blavatsky was forever concerned with the law of correspondence. Thus as she sees it, each Root Race repeats the corresponding Round (e.g. the 3rd Root Race of every Round as qualities of the Third Round).
Her anthropogony is as follows:
"Round 1. Man in the First Round and the First Race on...our Earth [Fourth Round] was an etheric being (a Lunar Dyani ["god"] as man), non-intelligent but super-spiritual [i.e. non-physical]....In each of the subsequent races and sub-races he grows more and more into an encased or incarnate being, but still...ethereal. He is sexless, and, like the animal and vegetable, he develops monstrous bodies corresponding with his coarser surroundings.
Round 2. He (Man) is still gigantic and ethereal, but growing firmer and more condensed in body....Yet still less intelligent then spiritual, for mind is a slower and more difficult evolution than is the physical frame.
Round 3. He is now a perfectly concrete...body, at first the form of a giant ape, and now more intelligent, or rather cunning than spiritual. For on the downward arc he has now reached a point where his primordial spirituality is overshadowed by nascent (human) mentality. In the last half of the Third Round his gigantic stature decreases...and he becomes a more rational being, although still more an than a Deva [god]. This is almost exactly repeated in the Third Root Race of the Fourth Round.
Round 4. Intellect has an enormous development in this Round. The hitherto dumb races acquire our present human speech on this globe, on which, from the Fourth Race, language is perfected and knowledge increases...."
Here we see a central thesis of Blavatsky's cosmology: the idea that human evolution passes through a serious of incredible transformations. Man begins as a mindless yet "spiritual" (perhaps one could say attuned to the greater cosmos, like a "nature-spirit" or angel), etheric entity, who takes on various giant and monstrous forms, before attaining his present statue and characteristics. This is basically the idea of emanation (progressive materialisation), but applied in a sequential, cyclic and evolutionary manner.