Explanation

In physiology, intussusception is the reception of foreign matter by living organisms and its conversion into food by ingestion, digestion and assimilation of food, including the whole process of nutrition and growth. It is the mode of interstitial growth characteristic of organic life. In botany, intussusception theory proposed by Nageli, the growth of cell walls by the intercalation of new solid particles between those already in existence. The intussusception theory is opposed to the theory of growth by apposition, which; supports that the new particles are deposited in layers on the inner side of the cell wall