Returning to the several British breeds, the conspicuous difference in
general appearance between Shorthorns, Longhorns (now rarely seen),
Herefords, Highland cattle, Alderneys, etc., must be familiar to every one.
A part of this difference may be attributed to descent from primordially
distinct species; but we may feel sure that there has been a considerable
amount of variation. Even during the Neolithic period, the domestic cattle
were to a certain extent variable. Within recent times most of the breeds
have been modified by careful and methodical selection. How strongly the
characters thus acquired are inherited, may be inferred from the prices
realised by the improved breeds; even at the first sale of Colling's
Shorthorns, eleven bulls reached an average of 214 pounds, and lately
Shorthorn bulls have been sold for a thousand guineas, and have been
exported to all quarters of the world.

Some constitutional differences may be here noticed. The Shorthorns arrive
at maturity far earlier than the wilder breeds, such as those of Wales or
the Highlands. This fact has been shown in an interesting manner by Mr.
Simonds (3/57. 'The Age of the Ox, Sheep, Pig' etc. by Prof. James Simonds,
published by order of the Royal Agricult. Soc.) who has given a table of
the average period of their dentition, which proves that there is a
difference of no less than six months in the appearance of the permanent
incisors. The period of gestation, from observations made by Tessier on
1131 cows, varies to the extent of eighty-one days; and what is more
interesting, M. Lefour affirms "that the period of gestation is longer in
the large German cattle than in the smaller breeds." (3/58. 'Ann. Agricult.
France' April 1837 as quoted in 'The Veterinary' volume 12 page 725. I
quote Tessier's observations from 'Youatt on Cattle' page 527.) With
respect to the period of conception, it seems certain that Alderney and
Zetland cows often become pregnant earlier than other breeds. (3/59. 'The