IN Hereditas, Bd. vi. (1925), which has just come to hand, there is an extremely interesting paper by Gote Turesson on “Plant Species in Relation to Habitat and Climate.” This author has grown in Sweden upwards of 10,000 cultures of various types and races of certain widely distributed plants, in order to ascertain the precise nature of the forms inhabiting different environments. Particulars are given concerning about fifteen species, with numerous illustrations.