@Lady of McCamley,  just curious.... is the rumpless/non-tailed trait dominant over the tailed gene?
		
 
		
	 
My head is not around all the genetics for rumplessness (say that fast 3 times). It appears mostly a dominant trait, unless the "normal" parent has genes which inhibit its expression and cause tail growth (which most chickens have). Other sources I have read indicated tails required more genetic code with genes for expression of that tail.
From what I can gather, there are 3 types of rumpless (tail-less) types.
Complete dominant (genetic)
Incomplete dominant (genetic)
Accidental (failure of tail growth due to environmental changes affecting the embryo during growth which can happen in any breed)
There also appears to be a recessive (genetic) type hat is more of a mutation that causes further deformities in the bird.
So the short answer is, somewhat dominant to dominant. Therefore, you can get tailed and rumpless offspring....unless the other parent has the genes to repress the rumpless gene and cause tail growth.
Rumpless is not necessarily a good thing for the bird (and therefore less likely to be bred forward in natural settings). Rumpless roos lose the ability to balance during mating causing reduced fertility (roos use their tail to stabilize during mating to assure close enough contact to the female, roos do not have an appendage), rumpless birds also lose a portion of the back bone which can also cause other problems with short backs, and they lose the oil gland located on the tail base.  Hatchability of rumpless birds has also been show to be reduced.
Add in the fact that the tufting gene also causes death in 25% of the chicks and you get something of a temperamental bird to breed. Hence why the Araucana is so rare and held by professional breeders rather than mass production hatcheries (as who wants to deal with all that and try to make profits?). The Araucana finickiness eliminated them from my list of breed choices as I developed my olive egger program.
I think I misquoted in my earlier post...the Collona were rumpless, pea combed and blue laying. The Quetro were tailed, tufted and laid a brown egg. The matings of those types produced what was known as the Araucana, a rumpless, pea combed, tufted, blue laying chicken...who could also genetically have tails and no tufts among siblings depending upon the genetic dice.
I'm not sure when the muff/bearding came in. I know that a number of Araucana types were imported from Chile at different times during the development of the Araucana and later Ameraucana, and that the original stock was not pure breeds in Chile, meaning you got a lot more genetics to work through in refining a stock that does breed true.
The Chilean stock came from Asian sources which has been verified genetically, and there are beards, crests, tufts found in Asian birds. The addition of the European fowl with the Spanish in the 1500's further muddied the waters. (You can see how trying to get a "true" Araucana out of Chile would have been difficult.)
Oh...and R.C. Punnet was not breeding for blue layers specifically, he was breeding for auto-sexing and tossed in blue Araucana blood for the fun of it as they were all the "rage" at the time. I summed that info too quickly in my earlier post. (Just want to be accurate).
LofMc
http://www.browneggblueegg.com/Article/Rumplessness.html
http://www.araucana.com/Rumplessness.htm