Abstract
Many kinds of Japanese aconites resemble well each other in internal structure of their tuberous roots. As the structural feature, the author aimed at the form of cambium, and created two specific values namely E/C and log10 (S2/C) to study on these forms stochastically. For their statistical calcutation rejectancial and fiducial ellipses are selected and as a result Japanese aconites are divided into five types roughly by averages.