VII.—Lack of Transmission of Avian Tumour Virus from Carrier Hens to their Offspring via the Egg

Abstract

The frequent reports of 20 per cent, or more losses due to neoplastic diseases in poultry flocks indicate that this is one of the greatest troubles of the industry. Though certain of the avian tumours have been favourite subjects for experimental cancer research, little attention has been directed to the problem of the ætiology and control of avian cancer itself. Consequently, despite the urgency of the problem, there is little information available which can be used as a basis for prescribing any preventive measures. It is not even known whether the majority of the spontaneous tumours are induced by a virus. Not many attempts have been made to transplant and study these tumours, considering the wealth of material available; and only a small proportion of the attempts have succeeded. Though most of these successfully transplanted sarcomas were found to be associated with a causative virus, it is impossible to state whether this is the usual condition of spontaneous tumours, or whether the few successful transplants were aberrant forms whose associated virus altered the growth characteristics and thus enabled a successful transplant to be made more easily.