Early descriPtion of the adult repiilian ovary include those of Von leydig ( 1853 ), WaldeYer ( l8?0 )' L:iraun {18?T), anC Loyez (1900, 1906). In ttirtles and lizards the ov' aries BrB round and PIUmP; in snahes, elongated; in l,he immature alligator, tlat and rather long (Reese' i915, Van den Erock, 1933; Forbes, 1_93).? 'fhe rlght ovaf,Y in'bhe lizards and E:raiies is more anterior in position tirsn that sf the treft side (Wiedersheim, 18BO). fhe clisappearance of $ne ovary or its failure to develop fully, which is tl4ical of some rept' iles and most birds, ls apparently due to the fact that at the stage of migration the majority of primordial germ cells colonise only tJre dominate gonad (WitscN, 1935; Stanley and Wltschi, 1940; Pasteels, 1g5B). An explanation for the uneven distritrr:.tion of primordial germ eells  between the two avian ovaries 'is that the right ovary is destined to be ironfirnctlonal receives ferver pri' morCiai germ rcils than the left one It is poorly vaseularized at the early si,ilges of development ( Dentsr: liakcfi, 1931, cited by Fra.nchi etal', ( 1962)