Cq, Cj, Co, Cg. — Acentric, monocentric, dicentric and tri- 

 centric. Chromatids are distinguished from chromosomes by 

 a single superscript for the former and a double superscript 

 for the latter: C^, CH. 



Cj, C2, C3. — The first, second and third 'generations' of vege- 

 tative propagation. 



C-mitosis. — The type of abnormal mitosis, produced by 

 colchicine treatment, in which the spindle is inactivated and 

 the chromosomes become scattered in the cytoplasm where 

 they form the characteristic configurations known as 'c-pairs'. 



C-pairs. — See under C-mitosis. 



Cacogenesis, Kakogenesis, — (i) Inability to hybridize 

 (Henderson), (ii) Deterioration of race or strain. 



Cacogenic, Kakogenic. Dysgenic, tending to impair the 



qualities of the race, or strain. 



Caenogenesis. — The production of a new evolutionary form 

 during ontogeny, especially the appearance of novel embryonic 

 features; youthful adaptation; clandestine evolution. 



Caenogenetic. — Of recent origin ; of a character which affects 

 only the young stages of ontogeny in a race. 



Calciferol. — CggH^^O, Vitamin Dg. 



Calycanthemy. — Petalody of the calyx; the formation of 

 coloured petal-like structures in place of a normal calyx. 



Calyciflorus. — Having calyx, corolla and stamens adnate. 



Calyx. — The outermost of tlie floral whorls. 



Canalicular Apparatus. — The Golgi Apparatus, q.v. 



Canalized Development Hypothesis. — The hypothesis that 

 although an organism may follow any one of a number of 

 developmental paths, it is difficult to make it develop along 

 lines intermediate between these possibilities because the in- 

 tegrated genotype acts as a buffering system, in such a way 

 as to limit the variation of the organism's response to environ- 

 mental fluctuations (Mather). 



Capitulum. — An inflorescence composed of numerous sessile 

 florets closely arranged on a receptacle e.g. Compositae. 



