According to the nomenclature coined by Z. Klement & R. N. Goodman, there exists a distinctive mechanism of acquired immunity which is exhibited in plants that have been subjected to pretreatment with a single bacterium, and consequently, is capable of shielding them from potential infection by other pathogens. However, it is noteworthy that this form of immunity, while noteworthy, is open to the same objection that applies to other forms of immunity, i.e., the term “immune” itself implies an exemption from infection and cannot be used to describe any degree of infection.