Knight — 52 — Dictionary 



Ergosterol. — Pro-vitamin D, CggH^^O. Vitamin D, the 

 anti-rachitic vitamin, is formed from ergosterol by irradiation 

 with ultraviolet light, 



Errera's Law. — A cellular membrane at the moment of its 

 formation tends to assume the form which would be assumed, 

 under the same conditions, by a liquid film destitute of weight. 



Erythrophilous. — Readily stainable with red dyes (as op- 

 posed to blue or green). 



Escape. — An apparently wild plant which is, in reality, not 

 truly wild, its presence being merely due to cultivation of this 

 type at an earlier date in the vicinity. 



Estrogens. — Oestrogens, q.v. 



Estrus. — Oestrus, q.v. 



Etheogenesis, Ethicgenesis. — Male parthenogenesis; the 

 formation of an organism from a male gamete without fer- 

 tilization having taken place. 



Ethnobiology. — The study of the relations between man 

 (especially primitive man) and his surrounding animal and 

 vegetable life. 



Ethnobotany. — The study of the relations between man 

 (especially primitive man) and his surrounding vegetation. 



Ethnozoology. — The study of the relations between man 

 (especially primitive man) and his surrounding animal life. 



Ethological. — Appertaining to custom, habit, or "behaviour 

 pattern" (c/. Mayr, 1942). 



Euapogamy. — The formation of a diploid sporophyte from 

 a gametophyte without fertilization having occurred; diploid 

 apogamy. 



Euchromatic. — Of a chromosome, or portion of a chromo- 

 some: staining less deeply (and presumed to consist of geneti- 

 cally active material), cj. Heterochromatic. 



Euchromatin. — See under Heterochromatin. 



Euchromocentre. — The heterochromatin on either side of 

 the centric constriction. 



Euchromosome. — An autosome; a normal chromosome, as 

 opposed to a heterosome. 



Eugenic. — Tending to improve the human race. 



Eugenics. — The application of the principles of genetics to 

 the improvement of a race (especially of humans). 



Eugenic Prognosis. — An estimate of the probability of a 

 given disease or defect being inherited (Blacker, 1934). 



Euhermaphrodite. — A normal hermaphrodite plant in which 

 both anthers and gynoecia are well developed in all flowers. 



