Pigeon milk’ is produced by A)Crop B)Birds C)Mammals D)All of the above
Option A) The best known of these secretions is the "crop milk" that pigeons feed to squabs. The milk is produced by a sloughing of fluid-filled cells from the lining of the crop, a thin-walled, sac-like food-storage chamber that projects outward from the bottom of the esophagus.
