Question

who proposed histogen theory

Answer 1

n the form it is presently understood, Charles Darwin presented a paper to the Linnean Society of London outlining his theory in 1858, which was read alongside an almost identical theory by Alfred Wallace. Darwin had been working on his theory for a number of years, summarised in an unfinished magnum opus, but seeing that Wallace was converging on the same idea he published an abstract of his book, titled On the Origin of Species, in 1859 to cement his version of the theory.

There were numerous precursors to Darwin’s theory. Jean-Baptiste Lamarck published his ‘transmutation’ theory 80 years earlier which featured progressive transformation and environmental adaptation, two of the cornerstones of Darwinism. Some ideas, such as lineage descent, date in crude form all the way back to the pre-socratic philosophers, although philosophers like Empedocles had no real grasp of a fleshed out evolutionary theory.

Answer 2

It was proposed by Hanstein (1870). According to this theory, the shoot apical meristem consists of three distinct meristematic zones or layers (or histogens).