322 Scientific Proceedings, Royal Dublin Society. 
the colours of their calves with a view to greater accuracy than 
commerce required ; and so some errors of description have crept 
into the herd-book. 
(6) White short-horns are of smaller money value than roans 
or reds, and consequently many are not registered at all. This 
happens especially with animals of little merit. 7 
(c) Among unscrupulous breeders the substitution of a coloured 
ealf for a white one is not unknown: a white calf’s pedigree being 
bestowed upon a roan or a red. 
To eliminate these sources of error as far as possible, I have 
collected a new set of data which is made up of every entry in 
volume lii. (published in November, 1906) of the Short-horn Herd- 
book by a number of breeders who may be expected, because of 
the high value of their cattle, to register a very high proportion of 
their calves, and who would not substitute one calf for another. 
Two of the sources of error cannot, however, be entirely elimi- 
nated, viz.: the error of wrong description and the error arising 
from some white calves not being registered. For instance, a bull 
standing now at the Albert Agricultural College, Glasnevin, was 
registered in the herd-book by his breeder, who is the most distin- 
guished breeder in England, as being red. This bull’s sire was 
white; his dam was red; and he ought therefore to be roan. He 
has bred several white calves from roan cows; and on this ground 
also he ought to be roan. On close inspection he is a roan, but 
such a roan as might easily be mistaken for a red. 
Amongst breeders the prejudice against white cattle is very 
strong, but especially against an animal some of whose ancestors 
were white. There is an impression that a white animal from 
roan parents may produce some white calves, but that a white 
animal from one or two white parents will produce many white 
calves. Consequently even in the best herds some white calves 
are not registered at all, more especially if they have a white 
parent. 
For the reason that white calves are not desired, two white 
animals are very seldom mated. Among the 2172 matings 
collected by Miss Barrington and Professor Pearson, only three 
such cases occur. In the 1023 matings which I have collected 
