The immunohistological method described here permits re-examination of previously Feulgen stained quail-chick chimera tissues for vascular development using the monoclonal antibody QH1 which specifically recognizes quail hemangioblastic cells. Weigert's iron hematoxylin has been used to restore faded or bleached Feulgen stained chimeric avian tissues. Species-specific differences in nuclear morphology are as evident with iron hematoxylin staining as they are with Feulgen staining.