Crossing of Poultry. 
59 
other words, over 99 per cent, were true to type. The remain- 
ing nine recorded as bay or brown are doubtless errors in the 
record, and it is interesting to note in this connection that 
further records of some of these same animals in the Racing 
Calendar give them as chestnut. 
A further series of records given in the Landwirthschaft- 
liche Jahrbiicher for 1888 by Crampe, and again by Wilckens, 
shows that chestnuts of any descent when bred together give 
nothing but chestnut in their offspring. 
Crossing of Poultry . — Owing to the fact that large numbers 
can be raised at a comparatively small cost, poultry have pro- 
vided very suitable material for the study of heredity. From 
the researches of Bateson and Hurst 1 it is now possible to trace 
in considerable detail the inheritance of most of the features 
characteristic of the various breeds. One case of exceptional 
interest is afforded by a study of the Blue Andalusian fowls. 
This “breed” proves to be a typical example of an unfixable 
first cross or DR. If, for instance, show birds are bred together, 
they do not produce simply Blue Andalusians, but three 
distinct types : white splashed, black, and some resembling the 
parent type. In an actual experiment of this sort the progeny 
consisted of 41 white splashed, 78 blue and 39 black birds, that 
is, they occur in the ratio of 1 : 2 : 1. One would expect from 
this that the whites and blacks would breed true to these 
characters, and further trials have shown that each type mated 
with its own colour breeds true. Further, if blacks and whites 
are mated, the resulting offspring are Blue Andalusians. To 
secure specimens of this breed, then, it would be policy to breed 
from the “ wasters.” All the resulting birds would then be Blue 
Andalusians, whilst if Blue Andalusians were bred from, the 
result would be that one-half only would reproduce the type. 
Turning to other colours, the white of the Leghorns is 
dominant over colour in the Houdans, Hamburghs, and 
Cochins, but the dominance is not complete, as flecking occurs 
in the feathers of the cross-bred birds. 2 In the same way the 
black of the Houdans and Hamburghs is dominant over buff 
in the Cochins. 
The comb characters have also been investigated in great 
detail. The single comb of the Cochins or Leghorns is re- 
cessive to the leaf comb of the Houdans, whilst the rose comb of 
the Hamburghs is dominant over the same singles and over leaf 
combs. In the generation bred from the hybrids in each case 
the two types appear in approximately the ratio of three to one. 
1 Report to the Evolution Committee of the Royal Soc., Parts I., II. and III. 
2 There is evidence to show that white may be of two sorts — one recessive 
to colour, the other dominant. Evol. Report Roy. Soc., Part III., page 18. 
Davenport, Inheritance in Poultry, Washington, 1906. 
