25 — Chondriomite 



Chiasma Theory of Pairing. — The hypothesis that when- 

 ever two chromosomes which have been paired at pachytene 

 remain associated until metaphase they do so by virtue of the 

 formation of a chiasma or visible exchange of partners amongst 

 their chromatids (Darlington). 



Chiasmatype Hypothesis. — The part of the chiasmatype 

 theory which supposes that chiasmata are determined by 

 crossing-over between two dissimilar chromatids of the four 

 involved (Darlington, 1932). 



Chiasmatype Theory. — The theory that crossing-over is 

 connected with chiasma formation. 



Chiasmatypy. — The process of chiasma formation together 

 with its genetical implications. 



Chimaera. — A plant composed of tissues of two, or more, 



genetically distinct types. See Burdo, Chromosomal , 



Dichlamidius, Diplochlamydeous , Graft Hybrid, Gynan- 



dromorph, Haplochlamydeous , Hyperchimaera, Mericlinal 



, Mixochimaera, Monochlamydeous , Mosaic, Peri- 



clinal , Polychlamydeous , Polyclinal , Sectorial 



, Trichlamydeous. 



Chiropterophilous. — Pollinated by means of bats. 



Chioranthy. — The reversion of petals to green leaves. 



Chlorophyll. — Two green chemical compounds, which to- 

 gether enable plants to obtain energy from light for use in 

 the synthesis of substances from carbon dioxide and water. 

 The two components are Chlorophyll a, C^^^2^^1:^^yi.g and 

 Chlorophyll b, CggH^gOgN^Mg; there are typically associated 

 with two yellow compounds, carotin, C^pH^g, and xanthophyll, 



^40^56^2- 



Chloroplast. — A small dense protoplasmic cell inclusion con- 

 taining chlorophyll sometimes accompanied by other pigments. 



Chlorosis. — A yellowing of the plant due to chlorophyll de- 

 ficiency; chlorophyll deficiency. 



Chlorotic. — Lacking chlorophyll. 



Choline. — A component of the vitamin B, complex. 



Chondriocont, Chondriokont. — A rod-like or thread-like 

 chondriosome. 



Chondriolysis. — Disintegration of mitochondria. 



Chondrioma, Chondriome. — The collective term for the 

 mitochondria of any individual cell. 



Chondriomere. — That part of a spermatozoon in which the 

 chondriosomes occur; plastomere. 



Chondriomite. — A linear type of chondriosome having the 

 appearance of a string of granules. 



