A34 QUEENSLAND AGRICULTURAL JOURNAL. [1 Junx, 1899. 
which those changes are to be attributed, are still in operation. These facts 
sufficiently account, as I shall try to explain later on, for the great variety of 
size, shape, colour, and disposition of the wild animals and plants that now 
exist. 
Some of the lowest forms of animals by which in primeval time the water 
and the land were solely inhabited are still in existence, some of them in slightly 
different forms. Whilst the animals were ascending from the lower to the higher 
forms of life, they developed in different directions; and we now meet with 
forms so widely different from each other as molluses, birds, fishes, quadrupeds, 
&c. Certain groups of animals are very similar to each other, such as goats 
and sheep, oxen, antelopes, deer, &e. ; 
In order to assign to certain animals their place in the animal kingdom, 
naturalists have divided the same into classes, orders, families, &c. The breeder 
of domestic animals is especially interested in what the naturalist calls genus 
(order), species (kind), and variety. ; 
By genus, we understand a group of animals very similar to each other, 
yet sufficiently unlike in their internal organisation as to preclude them from 
having offspring capable of permanent propagation. 
For instance, all the horse family, such as horses, donkeys, zebras, &c., 
belong to the genus Hguus, of which the domestic horse forms the species of 
Caballus ; the donkey, the species of Asinus, &e. All the members of the 
species Caballus, no matter how large or how small they may be, produce fertile 
offspring, but Oaballus does not produce with dsinus offspring capable of 
further propagating. Mules do not propagate mules. 
In breeding domestic animals and in attempting to form new kinds, it is 
important to clearly distinguish between genus and species with regard to goats 
and sheep. The question is by no means settled whether goats and sheep belong 
to the same species. Buffon professes to have frequently obtained offspring from 
male goats and female sheep; Schmalz mentions a certain flock of sheep in 
Poland descended from she-goats. According to the evidence on oath on the 
part of a shepherd, it appears that in the year 1871 a farmer named Bauer, 
living at Skludgewo, near Ostromeco, in Western Prussia, succeeded in obtain- 
ing six ram lambs out of twenty fine-woolled merino ewes that had been covered 
by a he-goat. To avoid any possible access of a ram to these ewes, they were 
kept away from the remainder of the sheep altogether. Many other authenti- 
cated instances are known of fertile crosses between goats and sheep. Several 
fiocks of such sheep-goats or goat-sheep are known to exist in Chili at the ~ 
present time. Some of them were imported to Germany, and are kept there at 
the present time. 
Fertile crosses of roes and sheep are also known to have occurred, but their 
offspring died soon after their birth. It has been observed that animals obtained 
by such heterogenous crosses were frequently more or less defective in their 
reproductive organs. In the meantime, we may argue from the fact that fertile 
crosses do occur amongst members of different orders even, such as of deer and 
sheep, that amongst the ruminants, for instance, there still exists a certain 
relationship, and that the common ancestors of the ruminant order have 
existed during a comparatively recent period of the world’s history. It is 
also worthy of notice that, during the process of evolution, a time arrived when 
certain groups of animals became so strongly differentiated in their internal 
organisation as to limit fertility. 
Where nature has drawn the line, or, in other words, of what kind have 
been the modifications in the animal body to effect this, we do not know. 
So much appears certain—namely, that, if each kind of our domestic animals 
were the result of a systematic creation for the special purpose for which it is 
now used, its type would have been very much more fixed at the time, and such 
fertile crosses as I mentioned would be impossible of creation. ‘Che possibility 
of producing offspring -at all between goats and sheep, hares and rabbits, &c., 
speaks in favour of the probability that goats, sheep, antelopes, deer, &c., have 
sprung from the same ancestors, whose descendants have become differentiated. 
