ABSTRACT
The greater mean cell volume is due to the presence of a large population of immature erythrocytes in circulation. The larger rbc of the younger chickens could have been a cohort that included some representatives that belonged to the primitive generation of erythrocytes which would be expected to be larger than definitive generation rbc. The sizes of erythrocytes of newly hatched altricial birds, at least in many instances, can be seen to diminish during their nestling period. The association of augmented sized erythrocytes with polyploidy has been experimentally authenticated in representative species from the major Classes of poikilotherms. Triploid and tetraploid whiptails have erythrocytes with appropriately enlarged nuclei. The dimensions of the erythrocytes obtained from geographically dispersed feral birds such as Columba livia the common pigeon, while a documentably quantifiable characteristic of a given species, can demonstrate considerable variation among less than strictly equivalent test subjects.
