Beside these inherent difficulties in deciding which forms are the most advanced in organisation, we ought not solely to compare the highest members of a class at any two periods-though undoubtedly this is one and perhaps the most important element in striking a balance-but we ought to compare all the members, high and low, at two periods.
Organizazioz zeintzuk forma diren aurreratuenak erabakitzeko ditugun barruko zailtasunez aparte, ez ditugu, aldi bitan, klase bateko gorengo kideak bakarrik konparatu behar-nahiz eta hau, balantzea egiteko orduan, dudarik gabe elementuetako bat eta agian inportanteena den-, baizik aldi bietako kide guztiak, goiko eta behekoak.