§ 2. PARTS OR ORGANS OF THE FLOWER 79 Floral Envelopes: Perianth, Calyx, Corolla 79 Essential Organs: Stamen, Pistil 80 Torus or Receptacle 81 § 3. PLAN OF THE FLOWER 81 When perfect, complete, regular, or symmetrical 81 Numerical Plan and Alternation of Organs 82 Flowers are altered branches 83 § 4. MODIFICATIONS OF THE TYPE 85 Unisexual or diclinous 85 Incomplete, Irregular, and Unsymmetrical 86 Flowers with Multiplication of Parts 88 Flowers with Union of Parts: Coalescence 88 Regular Forms 89 Irregular Forms 90 Papilionaceous 91 Labiate 92 and Ligulate Corollas 93 Adnation or Consolidation 94 Position of Flower or of its Parts 96 § 5. ARRANGEMENT OF PARTS IN THE BUD 97 Æstivation or Præfloration, its kinds 97 SECTION IX. STAMENS IN PARTICULAR 98 Andrœcium 98 Insertion, Relation, &c. 99 Anther and Filament. Pollen 101 SECTION X. PISTILS IN PARTICULAR 105 § 1. ANGIOSPERMOUS OR ORDINARY GYNŒCIUM 105 Parts of a complete Pistil 105 Carpels, Simple Pistil 106 Compound Pistil with Cells and Axile Placentæ 107 One-celled with Free Central Placenta 108 One-celled with Parietal Placentæ 108 § 2. GYMNOSPERMOUS GYNŒCIUM 109 SECTION XI. OVULES 110 Their Parts, Insertion, and Kinds 111 SECTION XII. MODIFICATIONS OF THE RECEPTACLE 112 Torus, Stipe, Carpophore, Disk 113 SECTION XIII. FERTILIZATION 114 § 1. ADAPTATIONS FOR POLLINATION OF THE STIGMA 114