FUR-FARMING IN CANADA 25 



There are now two methods by which he can proceed to secure 

 the black colour or pure B.B. 



When diverse colours are mated in foxes the hybrid sometimes 

 only, has the proportions within the blood and does not demonstrate 

 its parentage by its colour until the second generation. When the 

 crossing acts thus it is said to follow Mendel's law of hybrids. But 

 often the result is a blend giving a hybrid which has a proportion of 

 silver fur, i. e. a cross or patch fox. And it is not strange that foxes 

 in different districts breed thus for colour, as there are various examples 

 of the same phenomenon in different breeds of animals. Holstein 

 cattle segregate the colours; Shorthorns blend in some cases. 



Results: One-quarter of the litter is pure red 



One-half of the litter is red of the bastard type 

 One-quarter of the litter is black or silver 



Second method :_ RR + B.B. 



R.B. R.B. B.B. B.B. 



(red) (red) (pure silver (pure silver 



(or black) or black) 



Results: One-half of the litter is red of the bastard type 



One-half of the Utter is pure black or silver 



Thus, it may be concluded that, in a district where melanism 

 occurs, or where black and cross foxes occur, or either, there are very 

 few foxes bred pure as to colour. 



If the unit of union be regarded as of gametes which are produced 

 by each parent in the proportion of its ancestors — red and silver— 

 the results may be forecasted by a simple mathematical calculation, 

 the law of probabilities governing the mating of the gametes. 



R.R. + B.B. 



Red parent producing Black parent producing 



only red gametes only black gametes 



R.B. R.B. R.B. R.B. 



(red, bastard (red, bastard (red, bastard (red, bastard 



type) type) type) type) 



