The significance of an achondroplasia-like condition met with in cattle

Abstract

1. Dexter cattle are remarkable for their bodily conformation. They produce four classes of calves in such proportions as to suggest that the Dexter itself is a di-hybrid in respect of its characters : coat -colour and bodily conformation. A proportion of the calves are still -born and characteristic - :ally deformed, presenting certain constant features closely simulating those which constitute the condition of Achondroplasia in the human.2. The proportions in which these monstrous calves occur suggest that the 'bull-dog' calf results from the action of complementary lethal factors which are 'amplifying' factors producing an exaggerated form of the Dexter characterisation.3. The pituitary, thyroid and adrenals are abnormal. It is suggested that the lethal factor in this case is such as affects the proper and timeous functioning of the pituitary.4. The case of the 'bull -dog' calf is interpreted in terms of the factorial hypothesis and a suggestion is made as to the methods by which it can be eradicated through breeding.5. The possible bearing of the case of the monstrous calf of the Dexter upon the Species Question is briefly discussed.