J. Oort and J. P. A. Baak This manual is written by pathologists and is meant for pathologists. It deals with a subject that became especially popular in pathology at the end of the last decade: morphometry. Morphometry is defined as the quantitative description of a structure (Weibel, 1969). This structure may be both of macroscopic and micro- scopic size. Strictly, the size of an organ is a morphometric feature. This type of morphometry has long been in use in pathology. Examples ofthis type in diagnostic pathology have been given by Roesle and Roulet (1932). In this manual, however, the...