PRE FORMATION THEORY -

1. Proposed by Marcello Malpighi.
2. Studied chick egg and proposed his work in "De ova-incubato".
3. According this different part of embryo previously present in the eggs. These parts developed through the growth.
4. Swammerdam proposed that the sex cell contain preformed emrbyo or a more or a less perfect miniature of the adult.
5. Ovists view - This theory was supported by Malpighi, Spallanzani, Haller, Bonnet and swammerdam. These scientists belived that miniature organism was present in the eggs were called ovist.
6. Spermist view - Leeuwenhoek and Hartsoeker believed that miniature of organism was present in the head of sperm. This miniature is called hommunculus in man and animalcule in other animals.

Miniature in Mammalian Sperm