Light microscopic observations on the ossification process in the early developing pedicle of fallow deer (Dama dama)

The ossification process of the early developing pedicle was studied in five male fallow deer fawns, aged about seven months. The incipient pedicle was covered by a periosteum, the cambial layer of which was significantly thicker at the apex of the outgrowth than in the more peripheral areas of the pedicle. As was demonstrated histologically, in the central part of the pedicle elongation occurred by a process corresponding to endochondral ossification, whereas in the more peripheral areas the pedicle became enlarged by typical intramembranous ossification. Thus, cartilage formation must be regarded as a normal feature in pedicle growth of fallow deer. The assumption that the transition from pedicle to first antler growth in cervids is reflected by a switch from intramembranous ossification to chondrogenesis at the apex of the growing primary cranial appendage, based mainly on observations in roe deer, does, therefore, not hold for fallow deer. Furthermore, histogenesis of the central part of the fallow deer pedicle closely resembles the developmental events leading to formation of subsequent antlers.