In 1924 Paul Kammerer reported parent of origin effects in Midwife Toads with respect to the
water-mating phenotype that arose after exposure to an over-heated arid environment (Kammerer P.
1924. The inheritance of acquired characteristics. New York: Boni and Liveright). The paternal
phenotype was dominant over the maternal phenotype in reciprocal crosses. Historically regarded as
fraudulent Kammerer's finding have been re-examined by Vargas