By means of polyacrylamide gel electrophoresis, peroxidases of 59 species and 4 varieties, belonging to ten genera of Pinaceae, were analysed. Though intraspecific zymogramatic variation may be observed within a few species, each species possesses its specific zymogram, distinguishable from the others. In order to measure divergence between two taxa, we have defined “zymogram distance” as follows:

                                       number of different bands between two taxa   zymogram distance=        ——————————————

                                        total number of bands in the same two taxa