THOMPSON P E, BAYLES A, OLSZEWSKI B, WAITZ J A
Science. 1965 May 28;148(3674):1240-1. doi: 10.1126/science.148.3674.1240.
During induction of chloroquine resistance, Plasmodium berghei developed resistance to quinine administered in doses near the maximum amounts tolerated by mice. Resistant parasites did not form malarial pigment. Normal sensitivity to both quinine and chloroquine returned and pigment formation resumed during serial passage of the parasites through untreated mice.