Page 154. " And doesn’t it nearly always turn out that the breed with the higher yield is accepted in the end? Aren’t cattle crossbred to get hardiness, or milk-yield, or meat? "

A Belgian Blue cow. The defect in the breed's myostatin gene is maintained through linebreeding and is responsible for its accelerated lean muscle growth
GNU Free Documentation LicenseA Belgian Blue cow. The defect in the breed's myostatin gene is maintained through linebreeding and is responsible for its accelerated lean muscle growth - Credit: Kersti Nebelsiek
The selective breeding of plants and animals to emphasize certain genetic traits, such as milk yield, quality of meat and hardiness, has been carried out for many centuries.

 

Page 159. " one man displayed a head like a polished brown egg, without a hair on it, or on his face "

A woman with alopecia totalis
GNU Free Documentation LicenseA woman with alopecia totalis - Credit: Lovebug11768

Alopecia areata describes hair loss from part of the body, usually the scalp. It is believed to be an autoimmune disorder.

Complete loss of hair all over the body is Alopecia universalis. It is rare, with an incidence of one in 100,000 people. Alopecia totalis is a less severe form of the condition involving hair loss from the scalp alone.

Page 168. " Presently there were sparks as she used a flint and steel "
Assorted reproduction firesteels typical of Roman to Medieval period.
GNU Free Documentation LicenseAssorted reproduction firesteels typical of Roman to Medieval period. - Credit: Gaius Cornelius
Striking a flint with a piece of steel can be used to make sparks and therefore start a fire. A flint and steel is an old fashioned form of fire making that is many hundreds of years old.