This paper describes some changes in the physical properties of meconium apart from the exceptionably viscid state found in meconium ileus due to cystic fibrosis of the pancreas. The alterations in meconium described include: ano-rectal plugs, meconium plugs elsewhere in the intestinal tract, hard yellow meconium bodies contained within the green fluid mass of meconium, and pale yellow concretions associated with ulceration of the colon. The possible relation of disturbances in the motility and physiology within the intestine in the fetus to the formation of these abnormalities in the meconium discussed.