Cows which develop the behaviour and conformation of the male are known as “bullers.” Information obtained from breeders, veterinary surgeons, and butchers would seem to indicate that the phenomenon of partial sex-transformation in the cow is by no means of rare occurrence. The appearance of this condition is recognised by breeders as indicative of the onset of functional sterility, and any animal showing signs of becoming a “buller” is usually separated from the breeding-stock and prepared for the butcher before the assumption of the male secondary characters has reached a marked degree of expression.