Errata.

Page 206: For explanation of figs. 5 and 6 substitute—

Fig. 5.—Forewing of Zelandobius confusus (Hare).

Fig. 6.—Wings of Zelandobius hudsoni (Hare).

Page 574: In title, for Natural Self-fertilization read Natural Crossfertilization.

Page 795, in formula for y, numerator of last term should read cy (1—x), not Cy(1—x); and in formula for x the denomination should read cy, not Cy.