Culture of Human Marrow; Studies of the Effects of Roentgen-Rays

T H E monographs on the biologic action of roentgen-rays by Duggar1 and Scott2 and on the effects of roentgen-rays on the blood and blood-forming organs by Selling and Osgood 3 should be consulted for a review of the literature. Most of the research on the action of roentgen-rays has been done on insect eggs, lower animals or plants and those studies which have been made on human material have necessarily not been quantitative nor adequately controlled. Much of this research has been done with doses far above any that are ever used in clinical therapy. Scott, therefore, very logically states: (1) When any tissue is irradiated, careful measurement, both physical and biological, should be recorded. This may appear an obvious necessity, but neglect of the quantitative aspect of the biological action of radiations has been largely respon-sible for the errors, misunderstandings and controversies that are so apparent in the existing literature of the subject. (2) More information about the processes by which cells recover from the