The fine structure of plant tumors

Summary Crown gall cells of several plant species contain considerably more endoplasmic reticulum than their normal or hyperplastic counterparts. This characteristic appears to be stable even in crown gall tissues grownin vitro for many years. No evidence for the presence of an etiological agent was found in any of the crown gall cells, nor was there any evidence of any structure peculiar to these cells. It is not possible at this time to determine if this increase in endoplasmic reticulum is responsible for the increased biosynthetic capacities of tumor cells.