Experimentor

Mendel conducted his experiments in plant hybridization for ten years between 1854 to 1864 in the monastery’s 5 acre garden, testing as many as 28,000 plants, the majority of which were pea plants (Pisum sativum). He spent the first two years preparing by carefully selecting Pisum lines with constant characteristics and concentrated on seven pairs of traits that inherited independently of other traits: smooth vs. wrinkled, yellow vs. green, etc. In the spring, he would use tweezers to pollinate his plants and painstakingly tied tiny sacks around the flower of each plant to prevent cross-pollination. In the fall, he would study the peas, discovering a mathematical pattern. After 8 years, he established the rules of heredity, referred to as Mendelian inheritance. 

Photo: A page from Mendel's notebook listing crosses between various kinds of beans.

Photo credit: Gregor Mendel and the Roots of Genetics by Edward Edelson