1 Juny, 1899.] QUEENSLAND AGRICULTURAL JOURNAL. 23 
Crossing is not, as a rule, the method by which the best breeds are produced. 
It is still resorted to, however, by owners of common sheep, in the belief that 
crossing with highbred animals affords a much easier and shorter way of 
improving a breed than selection and inbreeding. The latter, on the other 
hand, is generally followed in the very best and the most inferior flocks—in 
superior flocks, because there might be no obvious necessity of infusing another 
kind of blood, particularly considering the danger that the blood freshly infused 
might be followed by serious reversions. Very common flocks are inbred, 
simply because the owners do not think it worth their while to attempt improve- 
ments. In some cases crossing becomes imperative if a breed is compara- 
tively free from the qualities we desire. The common merino flocks in Germany 
are produced through continued crosses of the common long-woolled country 
sheep with pure merinos. The mongrels so produced differ very slightly from 
their purebred ancestors on the side of the sire. There can be no doubt that 
we might succeed very well in making lasting improvements by continual crosses 
with superior blood if the general conditions are favourable. In a ease like the 
one I mentioned, crossing amounted really to what might be called an entire 
subjugation of the inferior blood. Animals of the fifth and sixth generations, 
roduced by fresh crosses, contain, practically speaking, scarcely any inferior 
blood at all, and they might answer very well for ordinary purposes; but we 
should certainly not attempt to use any of them for stud purposes. 
If crossing amounts to nothing more than amalgamating two breeds that 
have derived their distinctive characters through selection’ and inbreeding, but » 
have originally sprung from the same ancestors, it might be justifiable. If it 
were possible to amalgamate the densely woolled, regularly stapled, and well 
covered Saxon merinos with the longer stapled and open woolled sheep of 
Victoria, such as the old Ercildouns and similar types, we might eventually 
establish breeds of the highest possible perfection that can be attained. TI for 
one doubt whether such an amalgamation would be successful, except after 
a long time, owing to the great constancy of transmitting which either of these 
breeds possesses. 
Some breeders make periodical infusions of fresh blood into their flocks 
simply for the purpose of avoiding anything that might approach in-and-in 
breeding, for fear of destroying the constitutions of their sheep. I have already 
made suitable comments on that point. Others, again, keep on crossing 
individuals of two distinct breeds in order to obtain halfbred stock to be reared 
and fattened for the butcher. As the crossbred wool obtained from crosses 
between the heavy English breeds and merinos has fetched very satisfactory 
prices, many of such crosses have been carried out in almost every part of 
Australia, and the crossbred sheep do quite as well in North Queensland as 
they do in the Southern colonies. If that style of wool should be in permanent 
demand, and fetch good prices, it might be better to import an English breed out 
of which even a better style of that class of wool might be developed. 
It is evident that those who are desirous of im proving a breed by crossing 
will have to deal with the following questions:—1, What degree of inheritance 
does either of the two breeds possess? 2. Are the animals that are to be 
crossed very different in external appearance, and what kind of animals were 
the ancestors of either side with reference to the qualities we wish to cultivate, 
and to the degree of inheritance they are likely to exercise ? 
In the foregoing explanations I have tried to explain the general principles 
of breeding domestic animals, as they are—Ilst, based upon the results of 
scientific inquiries on the part of naturalists ; 2nd, backed up by the most 
successful practical breeders. I shall now mention a few facts that will serve 
to illustrate the principle of transmission generally. It has been observed that 
“if animals of a common stock are crossed with thoroughbred ones, it mostly 
happens that theimproving influence of the thoroughbred animals is chiefly noticed 
about the head, the neck, and the forequarters. The hindquarters are said to 
exhibit a greater tendency to resist the refining influence of the thoroughbred 
sire.” From my own observation amongst sheep, I am inclined to think that 
