Induced Dissociation of Walker Tumour 256 into its “Carcinomatous” and “Sarcomatous” Patterns of Growth

Abstract

The Walker tumour of the rat, a characteristically bimorphic tumour (Stewart et al., 1959), grows on the chorioallantois of the chick embryo after topical inoculation with a different microscopic architecture depending on the temperature of incubation of the egg (Leighton et al., 1963). In our studies an inoculum consisting of two or three drops of Walker tumour ascites fluid, was placed on the dropped chorioallantoic membrane of eight- or nine-day-old chick embryos. The embryos were maintained as before at the normal temperature of incubation, 38° C. On the eleventh day of embryonic life the inoculated eggs were candled. Of the viable eggs 10% were harvested for histologic study while the remaining ones were divided into three equal groups.

This work was supported by Research Grant No. Ca-02800 from the U.S.P.H.S., National Cancer Institute.