Chromoplast — 29 — Coenogamete 



pellicle at prophase, and constituting, as a spiral, the meta- 



phase chromosome (Darlington). 

 Chromosomin. — A special protein in cell nuclei, thought by 



some to be the principal constituent of chromosomes (others 



hold nucleoprotein to be the principal constituent). 

 Citrin. — Vitamin P. 

 Clandestine Evolution. — An evolutionary change, or trend, 



brought about, in the first instance, by an alteration in the em- 

 bryonic or larval stage which is followed by its inclusion in 



the adult as a result of neoteny or f oetalization ; caenogenesis. 

 Cleavage. — The cell divisions which transform a fertilized 



ovum into an embryo. 

 Cleavage Nucleus. — The nucleus of the fertilized animal 



ovum. 

 Cleavage Polyembryony. — Polyembryony brought about by 



the separation of the zygote or young embryo into two or more 



units. 

 Cleistogameon. — A species which, in part, reproduces by 



means of cleistogamy (Camp & Gilly, 1942). 

 Cleistogamic, Cleistogamous. — With close fertiHzation, this 



taking place within the unopened flowers. 0pp. Chasmogamic. 

 Cleistogamy. — The state of having close fertilization, this 



taking place within the unopened flowers. 0pp. Chasmogamy. 

 Cleistogene. — A plant which bears cleistogamous flowers. 

 Cleistogeny. — The state of bearing cleistogamic flowers. 



Adj. Cleistogenous. 

 Climatic Race. — An ecotype which has arisen as a result 



of adaptation to a different climate from that in which 



the rest of the species grows. 

 Cline. — A geographical gradient in phenotypic characters 



(Ford). A general term covering populations within a species 



which show geographical or ecological variation, cf. Ecoclines 



and Geoclines. 

 Clone. — A collective name for all the plants asexually re- 

 produced from a common ancestor. 

 Coefficient o£ Destruction. — The percentage of progeny 



which must normally be eliminated in order to keep the 



progeny at a given level (Carpenter, 1938). 

 Coenobium. — Cenobium, q.v. 

 Coenocyte. — A multinucleate mass of protoplasm arising as 



a result of nuclear division without cytoplasmic division, cf. 



Syncytium. 

 Coenogamete. — A gamete with several nuclei. 



