The life of Robert Koch, the German country doctor who, working on his own with primitive equipment, became the 19th century's foremost bacteriologist, does not seem to respond well to the full length treatment. At both the adult and juvenile levels, his story comes to dramatic life in short essays. The best of the adult titles with pages on Koch are De Kruif's Microbe Hunters and Baron's Man Against Germs. Both of these books are not above the grasp of good readers in jr. high school. The best juvenile collection does a particularly good job in Koch's case -- the Reidmans' Portraits of Nobel Laureates in Medicine (1963 p. 1011, J-303). All of these books avoid the fictionalized dialogue that fails to make Mr. Dolan's biography any more realistic by its presence. If anything, it is this that robs the attention from and divides the drama of Koch's original discoveries -- the microscopic identification of anthrax and t.b., the tuberculin test and the growth of bacterial cultures. The facts are all here, but the fictional adornment neither entertains nor helps to inform.