Conditioned Dominance — 33 — Crescents 



variations in number (eggs per bird, tubers per plant, etc.) 

 are discrete. 



Contraction. — See Condensation. 



Convergence. — The evolution of similar structures produced 

 by different means in different lines of descent. 



Convivium. — Convivum, q.v. 



Convivum. — A group, within a species, which is prevented 

 geographically from hybridization with the rest of the species 

 although fertility has not been lost, 



Co-orientation. — The relative orientation of the two centro- 

 meres on the spindle (Darlington). 



Copulation. — Coitus ; sexual intercourse. 



Core. — The endogenous sector of a periclinal chimaera. 



Corolla. — The interior perianth, composed of petals and often 

 brightly coloured. 



Corolla-tube. — The basal portion of a corolla in which the 

 individual petals are fused to form a tube, e.g. Primrose. 



Corpora Albicantia. — Small white bodies arising from cor- 

 pora lutea when ova liberated are not fertilized (Henderson). 



Corpora Lutea. — Yellow glandular bodies formed from the 

 Graafian follicles, after the extrusion of the ova, in Mammalia. 



Corpus Haemorrhagicum. — A body formed from the rup- 

 tured Graafian follicle (after the escape of the ovum) by the 

 closing of the cavity around the blood clot. The corpus 

 haemorrhagicum is the first stage in the development of the 

 corpus luteum. 



Corpuscular System of Heredity. — The plastid system of 

 heredity in which determinants, or units of heredity, are carried 

 by the plastids. cf. Nuclear System and Cytoplasmic System. 



Correlation Coefficient. — See Appendix 1. 



Coterminous. — Similar in geographic distribution. 



Cotypes. — The specimens on which the original description 

 of a species was based (Mayr, 1942). cf. Holotype. 



Coupling. — The state of having two linked recessive genes 

 on one chromosome and their two dominant alleles on the other. 



C.O.V. — Cross-over value, q.v, 



Cowper's Glands. — The homologue, in the male, of the glands 

 of Bartholin in the female. Cowper's glands are situated on 

 either side of the urethra, into which their ducts open, and 

 their function is probably to cleanse and neutralize the urethra 

 before ejaculation. 



Creative Evolution. — Evolution which follows a fore-or- 

 dained path. 



Crescents. — Part of the Golgi Apparatus, q.v. 



