Laxmi Bachanalaya
Legally available public-domain books and openly licensed reading materials.
Dmitry Ivanovich Mendeleyev
William Bateson and Gregor Mendel
Jacques Loeb
Reginald Crundall Punnett
J. T. Cunningham
These books are free to read. Each is in the public domain in the United States; check your own country's rules before you copy or share one.