Catecholamines 1922 -1971 H. BLASCHKO Adrenaline and related substances were discussed in the 1924 edition of Hefl'ter's Handbook by PAUL TRENDELENBURG. On 164 pages he described what was then known not only of adrenaline and its closest relatives but also of the sympathomimetic compounds such as tyramine and ephedrine. When the present Editors of the Handbook entrusted us with the task of editing the present Volume it was decided to restrict it to adrenaline and the other naturally occurring catecholamines. The sympathomimetic amines in general will be discussed only in their relation to the catecholamines. Since TRENDELENBURG completed his review this field has undergone an enormous expansion. There has been a wealth of new findings, and a succession of new ideas. The new theories that have been built into contemporary thought will be fully discussed in the succeeding contributions. But many of the hypotheses that have been put forward since 1924 have long been discarded and yet, they have often led to important observations that we still consider as valid.