18 QUEENSLAND AGRICULTURAL JOURNAL. [1 Juxx, 1899. 
Reversion generally means the reappearance of the bad qualities of some 
inferior ancestors, and we say that animals are degenerating if the reversion to 
inferior ancestors has been so frequent as to threaten a total loss of the good 
ualities we desire to cultivate and to fix. I have known several flocks in 
Gueeiae where the traces of the good rams that had been used at one time 
had become completely obliterated, so to speak. Bad qualities had sprung up 
again and increased. Darwin explains the nature of this reversion or throwing 
back by the following illustration :— 
“Some facts in regard to the colouring of pigeons well deserve considera- 
tion. The rock-pigeon is of a slaty blue, and has a white croup. ‘The tail has 
a terminal dark bar, with the bases of the outer feathers externally edged with 
white, the wings have two black bars. Some semi-domestic breeds, and 
some apparently truly wild breeds, have, besides the two black bars, 
the wings chequered with black. These several marks do not occur 
together in any other species of the whole family. Now, in every one 
of the domestic breeds, taking thoroughly wellbred birds, all the above 
marks, even to the white edging of the outer tail feathers, sometimes occur 
perfectly developed; moreover, when birds belonging to two or more 
distinct breeds are crossed, none of which are blue or have any of the above 
specified marks, the mongrel offspring are very apt suddenly to acquire these 
seats: To give one instance out of several which I have observed :—I 
crossed some white fantails, that breed very true, with some black barbs, and it 
so happens that the blue varieties of the barbs are so rare that T never heard of 
an instance in England, and the mongrels were black, brown, and mottled, T 
also crossed a barb witha spot, which is a white bird with a red tail, and red 
spot on the forehead, and: which notoriously breeds very true; the mongrels 
were dusky and mottled. I then crossed one of the mongrel barb fantails with 
a mongrel barb spot, and they produced a bird of as beautiful a blue colour, 
with a white croup, double black wing bar, and barred and white-edged tail 
feathers, as any wild rock-pigeon. We can understand these facts on the well- 
known principle of reversion to ancestral characters, confined, as far as I have 
seen, to colour alone, if‘all domestic breeds have descended from the rock-pigeon.”’ 
It is thus evident that some animals possess a higher degree of transmitting 
power than others ; but wherever the ossibility of tracing back to the qualities 
of ancestors is at hand, we shall proba ly find that the ancestors of such animals 
were in possession of those qualities in a high degree of perfection and con- 
stancy of blood. 
Such power is called “ prepotency.” It means a higher degree of trans- 
ferring power than usual. Some writers have maintained that ‘prepotency is 
a peculiarity apart from that power of transferring, which is the result of pure 
blood and high breeding ; that it is the result, rather, of a peculiar organisation 
of the individual ; and that it is, so to speak, a gift of nature, not to be eredited 
to descent from a series of superior ancestors.” 
However, there are no records in the history of breeding from which we are 
justified in presuming that such an individual prepotency really exists. In order 
to prove it, we must show authenticated instances that mongrels (7.¢., animals 
without claim to good blood) ever did become, dwing to such individual prepo- 
tency, the progenitors of a permanently superior race of animals. Such proof 
as never been given. Some animals certainly show a superior power than 
others of transferring their own good qualities, and occasionally in a higher 
degree of perfection. Such facts, however, can generally be explained as the 
results of a greater accumulation of good qualities in the blood of the animals 
_ in question, as derived from good ancestors. 
Settegast enumerates a number of instances where animals have produced 
exceptionally good offspring, in some cases much better even than they were 
themselves. The Shorthorn bull Hubback is credited by Settegast with that 
individual prepotency. It is well known, however, that Hubback was descended 
from the Teeswater cattle, a race then already famous for those very points which 
in a higher degree were the characteristics of Hubback. A few chance foals of very 
