About the theorist?

Question

in his work he related embryology to society,the different stages

Answer 1

You're going to have to be more specific. I know a lot about theory, but I have no clue what you're talking about.

My best guess is that you're referring to Auguste Comte, who was very invested in comparing sociology to biology. He said both societies and organisms have "multiple levels of organization". A nation is like the human body. Cities are like organs. Families are like cells. Individuals are like molecules. And so on.