Morning journal and courier., 1883-03-02
The Mechanics Course.

The Seventh Lecture-PrOfessOr Brewer
 on ''The DOmesticatiOn of AnimaIs"-A Large Audience and an Interesting
 Lecture.
 The seventh lecture of the course to me
 chanics was delivered by Prof. Brewer at the
 North Sheffield Hall last evening. The sub
 ject, 'sThe domestication of animals '' was a highly interesting one when treated by the popular lecturer, and was delivered in man ner to please as well as instruct. Illustra-
 tions representing swine of all kinds, from
 the wild boar to the modern American hog,
 were exhibited and compared during the
 course of the lecture. The speaker began by
 saying that the rearing and domestication of
 animals are of very old origin. 'tModern
 civilization said he, fuses domestic animals
 so largely that we could hardly do without
 them. The literature on the subject is vast, but
 it was by the publication of Darwin's works
 twenty-five years ago that the subject took a
 fresh start. What was or is the wild pro genitor of the horse, OK, dog or duck was up to that time comparatively unknown. No two animals are exactly alike-the children do not in all respects resemble their parents. This
 fact gave rise to the doctrine of the natural selection. This doctrine can be best ex- plained by discussing single species Let US
 take the hog as sample tonight.
 sOur ordinary swine was descended from 1 the wild boar, which roamed over Europe | and parts of Asia and Africa. The boar was | from thirty-four to forty eight inches in height, was little higher at the shoulders I than at the trump, it's legs were stout and l somewhat crooked and it's snout large and heavy. It had four prismatic tusks the ivory of which was very hard and brittle Ina nf ho fo,- l in ploughing up the ground-a process which we call rooting.' They were found in col ors varying from black, through brown, to a dirty red. In the young they were striped, ! the stripes running lengthwise of the body. | The females were partly gregarious; they had filters of from four to six in number and the young followed their mother for two l or three years. They were nocturnal in their l habits and fed upon acorns and nuts. They were very ferocious, as seen in the stories and pictures of ancient boar hunts
 s'Let us now see how we obtained the mod ern hog from the wild brutes just described. It was done by the process of natural seIec- | tion. With hogs, as with all other animals ! the weaker ones fail and the stronger ones | survive. Those with the biggest tusks to defend themselves from their enemies, the ! most hair to keep themselves warm, the I strongest snout with which to root when food is scarce, live the longest. In this manner the strongest live and breed provid- ed the animals are Tn 8 wild state. Now
 when man instead of killing the wild boar captures it, feeds and protects it from the cold and its enemies change, takes place in I the animal very soon. The snout wastes away for lack of use and the tusks are no longer required. The breeder selects those l anim als having the smallest teeth and snout and those which | are the quietest, fattest and largest. | Thus the process of selection goes on. By and by the skin becomes thinner and the hair ! scarcer. As this selection goes on differences of breed are noticed. The short -nosed breed now so popular in the West was produced by auntxing up of the Chinese swine with the European breed. The object of the breeder has been to increase the size of those parts of the animal which bring the highest price. Thus the heads of our hogs are small and their hams large.
 Domestic animals differ from wild ones in
 three essential particulars; they breed freely in captivity, are able to live under restraint and their very instincts are tanned. believe that in all animals there is an inherent tendency to va- riation. This variation is 6 biological force which may be directed by outward circum- stances. There is limit to this variation, for 1t is biological principle that one part detriment to some other part. Along with the fatness of hog come all the attendant diseases of fat animals. Thousands of pigs die from paralysis and fatty degeneration of the heart. As it is they are entirely depend ent upon man and if left alone would perish from hunger.,n
 The next lecture will be given next Tues-
 day evening by Prof. Dubois. The subject
 is 'sHeat and work"