There were three major theories on the basis of inheritance that existed prior to Mendel. Each of these periodically gained and lost popularity over time, but remnants of each existed well into the nineteenth century. These included: Pangenesis - Pangenesis is the belief that each part of the body contributed a miniature version of itself to the offspring. For example, each fingerwould contribute a small version of itself, as would each ear and toe. Preformation - The theory that a tiny preformed human, called a homunucleus, resided inside of either the egg or sperm cell. This was later adapted to the idea that all parts of the adult are formed early in the developmentof the zygote, and simply increase in size over time. Blending - Under this theory, offspring represented a mixture of the hereditary material. The hereditary material was not a distinct particle, but rather a malleable substance that could be changed over the course of a few gen-erationslt are formed early in the developmentof the zygote, and simply increase in size over time.
