The flock at the Poultry Research Centre (Greenwood and
Carr, 1951; Campbell, 1963a) Is considered to be free from
leucosis, and since no case of leucosis has arisen in birds
injected with the osteopetrosis preparations, the assumption has
been made that the virus 'strain* is, in fact, free from leucosis producing agents.
Since the gross pathology of the disease has been adequately
reported, the experiments reported in this work have been directed towards the characterisation of the virus, rather than the
effect on the infected cells. On these assumptions, a series
of experiments has been carried out, which aimed at showing
1. that osteopetrosis is, indeed, transmissible by a virus;
2. the character of the virus;
3. the behaviour of the virus in vitro, with a view to
developing an assay method;
4. the life cycle;
5. the relationship, if any, of osteopetrosis with the
leucosis complex and the transmissible R.P.L. 12 lymphoid tumour.