Now let's look at development from the medical point of view:

Carl Ernst Bock, MD, lived (1809 - 1874). Was a German anatomist.

He described stages of development as follows:

The stage years of human life.

All organic or living bodies, to which one counts the plants, animals and humans, are given by nature a certain duration of their existence, a life span.

During this time, the matter of these organisms is continuously subject to the so-called metabolism (see Gartenlaube Jahrg. I. No. 39. p. 423) and at the same time each organism passes through a fixed series of certain changes, which have been named developmental stages, life stages, life ages, life epochs, life phases or educational periods.

In every organism it can be clearly seen how it comes into being, grows, reaches a certain stage of perfection (maturity), remains on this stage for some time, then gradually decreases in perfection again and finally perishes (dies), after it has produced (reproduced) organisms similar to its own organism in the time of maturity.

Music:  Python - Emmertsgrund