130 THE HISTORY OF CREATION, 
developed into the Prothelmis, the common primary form 
of Worms (Vermes). (Compare p. 133.) 
This latter tribe (as limited by modern zoology) is of the 
greatest interest in the study of genealogy. For among 
Worms, as we shall see later, there are, besides very nume- 
rous peculiar families, and besides many independent 
classes, also very remarkable forms, which may be con- 
sidered as forms of direct transition to the four higher 
animal tribes. Both comparative anatomy and the on- 
togeny of these worms enable us to recognize in them 
the nearest blood relations of those extinct animal forms 
which were the original primary forms of the four higher 
animal tribes. Hence these latter, the Molluscs, Star-fishes, 
Articulated animals, and Vertebrate animals, do not stand 
in any close blood relationship to one another, but have 
originated independently in four different places out of the 
tribe of Worms. 
In, this way comparative anatomy and phylogeny lead us 
to the monophyletic pedigree of the animal kingdom, the 
outlines of which are given on p. 133. According to it the 
seven phyla, or tribes, of the animal kingdom are of different 
value in regard to genealogy. The original primary group 
of the whole animal kingdom is formed by the Primeval 
animals (Protozoa), including the Infusoria and Gastreeads. 
Out of these latter arose the two tribes of Animal-plants 
(Zoophyta) and Worms as diverging branches. Out of four 
different groups of the Worm tribe, the four higher tribes 
of the animal kingdom were developed — the Star-fishes 
(Echinoderma) and Insects (Arthropoda) on the one hand, 
and the Molluses (Mollusca) and Vertebrated animals 
(Vertebrata) on the other. 
