A. BarrinCtTon and K. Pearson 
431 
cattle, although of great value for trade purposes, do not form the subject of any 
herdbook record. Still it seemed possible to obtain some simple results by an 
appeal to large breeders of blue-greys. Their returns form the subject of the first 
part of the present paper. We next endeavoured to obtain some general idea of 
the colour inheritance of British cattle, but the colours of the original progenitors 
of existing types seem very hypothetical, and our researches in this direction, 
embodied in a later part of this paper, are not very helpful. Attention was then 
devoted to two types : the shorthorn and the Guernse3\ In the case of the former 
Goates Shorthorn Herdbook, issued by the Shorthorn Society of Great Britain and 
Ireland, has now reached the fiftieth volume, and we have to heartily thank the 
Society for placing a copy of it at our disposal for the present investigation. This 
herdbook is very complete in character and deals with very large numbers of 
beasts. At least some breeders insert the coat-colour of calves sent to the butcher, 
but we doubt whether such entries are universal. In the case of the Guernseys, 
the English Guernsey Herdhooh has appeared for eighteen years, the pedigrees lead 
fairly soon back to the Guernsey Guernsey Studbook, of which ten volumes had 
appeared up to date. We have to heartily thank the English Guernsey Society fin- 
placing a copy of their herdbook at our disposal. We supplemented it by the 
purchase of the Guernsey Guernsey Studbook. The latter seems to us a less reliable 
work, as cattle are included with many coat-colours, which would not be admitted 
now into the English Guernsey record. But a full discussion of this matter is 
postponed until we come to deal with Guernseys in the second half of this paper. 
Pedigrees with the statement of coat-colour were filled in for shorthorn and 
Guernsey cattle from these herdbooks, and to obtain an adequate supply of such 
pedigrees has demanded a large amount of very laborious work. We shall now 
take our subdivisions in order : 
(3) Blue-Grey Cattle. Colour 1 nheritatice. 
In this case the blue-grey cattle are as a rule produced by crossing a black 
polled Galloway cow with a white shorthorn bull. The white shorthorn (with black 
eyes) and the black cattle breed relatively true, so that if we term one B and the 
other W we might test a simple Mendelian formula {BB) x {WW) = {BW), 
and then further investigate the crosses {BW)y.{WW), {BW)x{BW) and 
{BW) X {BB). 
As in the case of Japanese waltzing mice crossed by Albino white mice we do 
not meet with any simple phenomenon of dominance, the general coat-colour of 
the offspring being blue-grey. The problem therefore turns on the action of these 
hybrids. Our first enquiry was as to the nature of the shorthorn bull purchased 
by the blue-grey cattle breeders. Mr H. L. Fife, of the Raby Estates Office, 
speaking of experience with the sales of produce from the Raby herd, writes : 
"Breeders of blue-grey cattle in the North-West of England, who produce the same by crossing 
a white shorthorn bull with a black polled cow, are always most particular when buying a 
white sire to satisfy themselves if possible, that such sire is the produce of two white parents. 
If he is not, that is to say, if the parent on one side only is white, their theory is that his stock 
when crossed with black cows do not get the blue-grey colour they like." 
