1834), who in 1866, seven years after the publication of Darwin's Origin of Species, published his suggestive Generelle Morphologic. Haeckel introduced into classification a number of terms intended to indicate the branchings of a genealogical tree.
The whole " system " or scheme of classification was termed a genealogical tree (Stammbaum); the main branches were termed " phyla," their branchings " sub-phyla "; the great branches of the sub-phyla were termed " cladi," and the " cladi " divided into " classes," these into sub-classes, these into legions, legions into orders, orders into sub-orders, suborders into tribes, tribes into families, families into genera, genera into species.
Additional branchings could be indicated by similar terms where necessary.
- It is obvious that the Linnaean binomial terminology and its subsequent trinomial refinement for species, sub-species, and varieties was adapted to express the differences between animals as they exist to-day, distributed contemporaneously over the surface of the earth, and that it is wholly inadapted to express either the minute gradations of successive generic series or the branchings of a genetically connected chain of life.