394 READINGS IN EVOLUTION, GENETICS, AND EUGENICS 
Dominant Recessive 
LOCKS wei ac acs teitiea wanes Coloured White 
Wheat and barley.......... Beardless Bearded 
Later ripening Rivett Early ripening Polish 
wheat wheat 
Non-immune to “rust” Immune to “rust” 
Ma IZe seeiiio so mecmenehoes “Starch” seed “Sugar” seed 
Nettles (Urtica pilulifera and 
U. dodartit)............44 Serrate leaf margin Entire leaf margin 
Mirabilis jolapa and M. rosea. Rose colour Other colours 
MICE seats sueltates esas aisacenaniasieldis Coloured coat Albino coat 
Normal “Waltzing” variety 
Rabbits. ...............005 Coloured coat Albino coat 
Angora fur Short fur 
POU tis ss pave ig eer oa “Rose” comb of Ham- High serrated “single” 
burghs and Wyandottes comb of Leghorns and 
Andalusians 
Cattle cectrtiaios dansnnaee Hornlessness Horns 
SHAS onc ieomuadsiwde Bandless shell Banded shell 
Other instances in plants.—As is well known, there are two almost 
equally common forms of wild primrose: (A) thrum-types, with 
short styles and with anthers at the top of the corolla-tube; and (B) 
pin-types, with long styles and with anthers half way down the tube. 
The thrum-type is dominant over the pin-type. 
The original species of Chinese primrose (Primula sinensis) has a 
palmate leaf. About 1860 a sport arose (from seed) which had a 
pinnate or “fern” leaf. The palmate form is dominant, and the fern 
leaf is recessive. 
The deformed “Snapdragon” variety of sweet pea behaves as a 
recessive to the normal type. 
The 2-row barley has certain lateral flowers which are exclusively 
staminate; in 6-row barley all the flowers are staminate and pistillate, 
and all set seed. Mr. Biffen crossed these forms, and found that the 
more negative character was dominant. The offspring were 2-rowed. 
Maize.—When the common or starchy round-seeded maize is 
crossed with the wrinkled-seeded sugar-maize, the round starchy char- 
acter dominates. When an egg-cell of the wrinkled sugar-maize stock 
is fertilised by a pollen-cell of the round starchy stock, the result is a 
round seed with starchy endosperm. If this seed is sown, it becomes 
a plant which, on self-fertilisation, forms a cob with a mixture of 
round starchy and wrinkled sugary seeds in the ratio 3:1. The 
wrinkled seeds yield sugar-maize; the round seeds yield two “impure 
rounds” to one “pure round.” Correns has observed a very inter- 
esting case in which two pairs of contrasted characters are implicated. 
