The foundation of Zoology as a Science
Gave the first accurate description on how blood circulation works.
Discovered a correaltion between fossils and geological strata
Animal electricity (measuring electric phenomenon of animals)
Studied and published works about the nature of plankton
Concept of homology and anaology
Discovery of Chromosomes
Distribution of animals on basis of zoological regions.
Discovery of blood groups
Constitution of the diploid group of chromosomes.