The interrenalchromaffin tissue ratio (IC ratio) in the adrenal gland of Kuttanad ducks was studied during post hatch development in 78 female birds of 13 age groups from day-old to 24 weeks of age at fortnightly intervals. The measurement was read out from the pictures by the use of “ImageJ software”. The proportion of interrenal tissue in the whole gland was least at sixth week of age (1.15:1...