Ceylon, plants of, [375].

Chalk formation, [322].

Characters, divergence of, [111].

——, sexual, variable, [156].

——, adaptive or analogical, [426].

Charlock, [76].

Checks to increase, [67].

—— ——, mutual, [71].

Chickens, instinctive tameness of, [216].

Chthamalinæ, [289].