CHAPTER I.

DEFORMITIES 311

Formation of tubes, 312--In flower, 314--Spurs, 315--Contortion, 316--Spiral torsion, 319--Of leaf, 326--Adventitious tendrils, 326--Interrupted growth, 327--Cornute leaves, 328--Flattening, 328.

POLYMORPHY 329

Heterophylly, 330--Dimorphism, 333--Sports or bud-variations, 336.