VI

CONTEXTS.

CHAPTEE VII.

Summary of the Heights and Weights of the Crossedand Self-fertilised Plants.

Number of species and plants measured — Tables given — Pre-liminary remarks on the offspring of plants crossed by a freshstock—Thirteen cases specially considered — The effects ofcrossing a self-fertilised plant either by another self-fertilisedplant or by an intercrossed plant of the old stock — Summaryof the results — Preliminary remarks on the crossed and self-fertilised plants of the same stock — The twenty-six exceptionalcases considered, in which the crossed plants did not exceedgreatly in height tho self-fertilised — Most of these cases shownnot to be real exceptions to the rule that cross-fertilisation isbeneficial — Summary of results — Relative weights of thecrossed and self-fertilised plants.Page 238-284

CHAPTEE VIII.

Difference between Crossed and Self-fertilised Plants inConstitutional Vigour and in other respects.

Greater constitutional vigour of crossed plants—The effects of greatcrowding — Competition with other kinds of plants — Self-fer-tilised plants more liable to premature death — Crossed plantsgenerally flower before the self-fertilised — Negative effects ofintercrossing flowers on the same plant — Cases described —Transmission of the good effects of a cross to later generations— Effects of crossing plants of closely related parentage —Uniform colour of the flowers on plants self-fertilised duringseveral generations and cultivated under similar conditions.

285-311

CHAPTEE IX.

The Effects of Cross-fertilisation and Self-fertilisationon the Production of Seeds.

Fertility of plants of crossed and self-fertilised parentage, both lotsbeing fertilised in the same manner—-Fertility of the parent-plants when first crossed and self-fertilised, and of their crossed