1 76 GLOSSARY. 



Cupule (a little cup). The gemma-cup of liverworts. 

 Cuticle (the skin). The outermost layer of the epidermis, 



differing chemically from the remainder of the cell- wall. 

 Cyanophyceae (blue seaweeds). A group of Algae commonly 



known as blue-green Algae. 

 Cyclic. Applied to an arrangement of leaves or floral organs 



in which two or more appear upon the axis at the same 



level, forming a cycle or whorl. 



Cystocarp (bladder-fruit) . The spore- fruit of some Thallophytes. 

 Dehiscence (gap or opening). The opening of an organ to discharge 



its contents, as in the case of anthers, sporangia, capsules, etc. 

 Dermatogen (skin-producer). The layer of nascent epidermis 



in the meristem of growing points. 



Dichotomous (cutting in two). Forking regularly by pairs. 

 Dicotyledonous (cotyledons double). Having two cotyledons, 



or seed-leaves. 

 Dioecious (two households). Having the two sex-organs 



borne by separate individuals. 

 Dorsiventral. Having the two surfaces differently arranged with 



reference to the surroundings to which they are exposed. 

 Elater (a driver, or hurler). Spirally thickened cells within 



the sporogonia of some liverworts, which assist in expelling 



the spores; also special spore-distributing structures in 



Equisetum. 



Egg, or oosphere. The female gamete. 

 Egg-apparatus. A group of three cells consisting of the egg 



and two synergids that lie at its sides. 

 Embryo (fetus, or beginning of a new individual). The young 



plantlet within the seed. 

 Embryo-sac. The cavity, within the nucellus, in which the 



embryo develops. 

 Endodermis (within the skin). The layer of cells inclosing the 



fibro- vascular bundle; the bundle-sheath. 

 Endogenous (produced within). Originating from internal 



tissues, and penetrating the outer ones. 

 Endosperm (within the seed). A parenchymatous tissue 



developed within the embryo-sac. 

 Endosperm nucleus. The nucleus formed in the Angiosperm 



embryo-sac by the union of two polar nuclei, one from 



each end of the embryo-sac. 



Endospore (within the spore). The inner layer of a spore- wall. 

 Endothecium (within the case). The inner wall of the theca.. 



