242 GLOSSARY 



Fungi. Spore-plants without chlorophyll, parasitic on other 



organisms, or growing on the products of their decay. 

 GynoRceum. The part of a flower in which the ovules are 



produced. - 



HeterospoTous. Producing two kinds of spores: microspores 



(male) and megaspores (female). 

 Homosporous. Producing only one kind of spore. 

 Hypogynous. Inserted below the pistil; used of the stamens 



and corolla. 

 Indusium. A membranous coat enclosing a sporangium or 



group of sporangia in Ferns. 



Integument. A coat or envelope of an ovule or seed. 

 Lichen. A plant made up of an Alga and a Fungus, living in 



close association. 

 Medullary ray. A vertical plate of cells, running through wood 



and bast in the direction from pith to cortex. 

 Megasporangium. A sporangium containing megaspores. 

 Megaspore. A large spore, producing the female prothallus. 

 Micropyle. The opening in the coats of an ovule, through 



which the pollen-grain or pollen-tube enters. 

 Microsporangium. A sporangium containing microspores. 

 Microspore. A small spore producing the male prothallus, 



which is almost reduced to an antheridium. 

 Nucellus. The central part of an ovule or seed, surrounded by 



the integument, and containing the embryo-sac. 

 Nucleus. That part of the living body of a cell by which its 



development and multiplication are controlled. 

 Ovary. The part of the pistil in which the ovules are contained. 

 Ovule. The young seed before fertilisation. 

 Palaeontology. T,he study of fossil plants and animals. 

 Parasite. A plant which grows on another plant and feeds 



upon it; like Dodder on Furze. 

 Perianth. The envelope of a flower, including calyx and 



corolla. 



Pericarp. The wall of a fruit, enclosing the seeds. 

 Petals. The leaves of the corolla. 

 Pistil. The central part of a flower, composed of one or more 



carpels and enclosing the ovules. 

 Potten. The cells discharged from the stamens; they produce 



the male cells and correspond to the microspores of Spore- 

 plants. 



Pollen-sac. A sporangium in which pollen is formed. 

 Pollen-tube. The outgrowth produced from a pollen-grain on 



germination; it conveys the male cells to the egg-cells. 



