CONTENTS 



Preface v 



1 . Historical Sketch 1 



Discovery of Pollen Tube — Schleiden's Theory of Origin of Embryo — 

 Discovery of True Relation between Pollen Tube and Embryo — Discovery 



of Sexual Fusion in Lower Plants — Discovery of Nature and Development 

 of Male and Female Gametophytes — Embryo — Discovery of Syngamy — 

 Chalazogamy — Double Fertilization — Parthenogenesis — Twentieth Cen- 

 tury — References. 



2. The Microsporangium 28 



Wall Layers — Sporogenous Tissue — Cytomixis — Cytokinesis — Microspore 

 Tetrad — References. 



3. The Megasporangium 54 



Integuments — Micropyle — Nucellus — Integumentary Tapetum — Hypo- 

 stase— Epistase — Vascular Supply of Ovule— Arch esporium — Megasporo- 

 genesis — Functioning Megaspore — Failure of Wall Formation during 

 Meiosis — References. 



4. The Female Gametophyte 84 



Monosporic embryo sacs — Polygonum Type— Oenothera Type — Bisporic 

 embryo sacs — Allium Type — Tetrasporic embryo sacs — Peperomia Type — 

 Penaea Type — Drusa Type — Fritillaria Type — Plumbagella Type — Adoxa 

 Type — Plumbago Type— Aberrant and unclassified types — Limnanthes 

 douglasii — Bahamita vulgaris — Chrysan themum cinerariaefolium — Or- 

 ganization of mature embryo sac — Egg Apparatus — Antipodal Cells — 

 Polar Nuclei — Embryo Sacs with Disturbed Polarity — Food Reserves in 

 the Embryo Sac — Embryo Sac Haustoria — References. 



5. The Male Gametophyte 154 



Microspore — Formation of Vegetative and Generative Cells — Division of 

 Generative Cell— Male "Cells" or "Nuclei"— Vegetative Nucleus— De- 

 velopment of Pollen in Cyperaceae — Embryo-sac-like Pollen Grains — 

 References. 



6. Fertilization 181 



Germination of Pollen — Course of Pollen Tube — Entry of Pollen Tube 

 into Embryo Sac — Rate of Growth of Pollen Tube — Gametic Fusion — 

 Multiple Fusions and Polyspermy — Single Fertilization — Persistence and 

 Possible Haustorial Function of Pollen Tube — X-bodies — References. 



7. The Endosperm 221 



Types of Endosperm Formation — Free Nuclear Endosperm — Cellular 

 Endosperm — Helobial Endosperm — Relationships between Different 

 Types of Endosperm — Histology of Endosperm — Xenia — Mosaic Endo- 

 sperm — References. 



ix 



