INTRODUCTION -

1. Karl Von Baer - Coined the term cleavage. Swammerdom - First time seen cleavage.
2. Prevost and Dumas - Reported cleavage of frog's egg. Spllanzani - Detailed process of cleavage of frog's egg.
3. Balfour - Explained that, the rate of cleavage depend upon the amount of yolk.
4. Process of progressive subdivision of the zygote by mitotic cell division into an increasing number of cells of progressively decreasing size is called cleavage.
5. Clevage is a rapid mitotic division of zygote to form a hollow, spherical & multicellular embryo.
6. Cleavage is also called cellulation or segmentation.