Many biologists and other academics held to the idea of blending inheritance during the 19th century, prior to the discovery of genetics

Genetics

Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....

. Blending inheritance was merely a widespread hypothetical model, rather than a formalized scientific theory (it was never formally presented to a scientific body, nor published in any scientific journals, nor ascribed to any specific person), in which it was thought inherited traits were determined, randomly, from a range bounded by the homologous traits found in the parents.