| I have learned that
lately in many countries point Cornish rexes have been registered as so
called tonkinese si-rexes.
I tried to find out what color the kittens were
as newborn and why they have been registered as tonkinese points. The new
owners could not tell anything of the matter, and the cats I have seen,
have, in my opinion, been normal sirexes.
The owners of the cats have told that the reason
for the tonkinese registration had been the pale blue eyes of the cats. I
do not consider the pale blue to be confirmative feature for the cat to be
a tonkinese si-rex.
In the history of a pointed Cornish rex, we find
siamese cats from whom the point color originates. While point Cornish rex’s
have not been bred systematically but colors have been combined randomly;
this has effected the eye color of si- rexes. The color can be anything
between watery blue to sky blue, but the color is not as intensive as a
pure siamese should have.
What, then, is a tonkinese? It is a breed
diveloped in USA, by combining siamese and burmese.
The offspring show both siamese and burmese
colors. The colors have been divided by a chart into groups of color,
which contain very pale colors and various grades of darker shades.
Genetically the color of a tonkinese consists of one burmese gene and one
siamese gene. The tonkineses shown in pictures I have seen, have had
rather pale blue eyes, but the type code confirms the eyes should be more
greenish than blue.
Here the genes are competing over the eye color,
just like with the cornish rexes, with several color combinations. |
The probability to
have a tonkinese point in a Cornish rex litter is very small.
As mentioned before, both a siamese and a burmese must be found at the
background of the si-rex to produce a tonkinese. Cornish rexes have not
been mixed with other breeds for years, except in some few countries where
it is allowed to expand the genetic base.
We can use a simple chart to find out the
probability of getting some specific property. This chart makes it clear
that the further backwards in the generations we go, the less probable it
is to find this property in a cat. The burmese have been used to develop
rexes but most probably not as much as the siamese.
It is closer to 30 years since these combinations
have been used.
One of our cattery’s cats had a few years ago
two kittens with such a strange birth color, that we could not specify
them. They were beautiful beige!
We asked the breeder of the father if she knew
anything about this color, with no enlightment. When the kittens developed,
the points started to show and we verified the points.
We did some research to find out how a si-rex
is born with color and found some information of tonkineses with the same
color history. We also checked the male’s background, and there was,
note, as close as in the fifth generation a burmese. Our point female gave
the required siamese gene. We then called the color of our kittens
tonkinese point, which is also accepted in FIFE.
|
| The red si-rex male was born all white,
but red is a very pale color and the tonkinese coloring appeared
later. The blue one was clearly born colored, blueish. The first lilac
si-rex tonkinese was born very pale beige and the seal tonkinese ones were more strongly
colored. Now when I look at these kittens later, I can clearly see the
burmese effect. |
If you wonder if your
kitten would be a tonkinese si-rex, you can say nothing for sure, unless
its background contains rather close a burmese and/or your kitten has
color when born. The Cornish rex tonkinese point kittens had the eye color
closer to green than blue. Pale blue eyes do not guarantee that your point
rex is a tonkinese si-rex.
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