SOME ASPECTS OF THE MORBID ANATOMY OF PLANTS

The anatomical modifications in the tissues of plants caused by the action of gall-inducing fungi and insects are illustrated by a number of examples, and compared with those produced by various processes of regeneration and wound healing or by factors that lead to anatomical changes without the intervention of wounds, such as nutrition, humidity, and the like. It is concluded that all living cells have the potentiality to react to various stimuli by hypertrophy, hyperplasy, or the development of meristeroatic tissues, and that the pre-existing meristems are not, of necessity, primarily implicated in gall formation.