XXI. Mutations in horticulture. 604
Chelidonium majus lacinatum. Dwarf and spineless varieties. Laciniate leaves. Monophyllous and broom-like varieties. [xvi] Purple leaves. Celosia. Italian poplar. Cactus dahlia. Mutative origin of Dahlia fistulosa, and Geranium praetense in the experiment-garden.
XXII. Systematic atavism. 630
Reappearance of ancestral characters. Primula acaulis umbellata. Bracts of crucifers. Zea Mays cryptosperma. Equisetum, Dipsacus sylvestris torsus. Tomatoes.
XXIII. Taxonomic anomalies. 658
Specific characters occurring in other cases as casual anomalies. Papaver bracteatum monopetalum. Desmodium gyrans and monophyllous varieties. Peltate leaves and ascidia. Flowers on leaves. Leaves. Hordeum trifurcatum.
XXIV. Hypothesis of periodical mutations. 686
Discovering mutable strains. Periods of mutability and constancy. Periods of mutations. Genealogical trees. Limited life-time of the organic kingdom.
F. FLUCTUATIONS.
XXV. General laws of fluctuations. 715