13 
now the composition of the medium once bathing the bodies of 
aquatic ancestors. The famous poet Goethe makes use of his know- 
ledge as a scientist when he puts into the mouth of Thales in “Faust/* 
Part II., the words — 
“Alles ist aus dem Wasser entsprungen ! 
A lies wire! durch das Wasser erhalten ! 
Ozean, gorin’ uns dein ewiges Waltenj 
The following table indicates roughly the distribution of the 
chief animal groups respecting their habitat: — 
Land Animals. 
Protozoa . . . . 
Sponges, (few species in fresh water) 
Coelenterata (rare in fresh water) . . 
Platyhelminthes (fresh water and 
parasitic) 
Nemerteans-— (exceptional on land) 
Rotifera — (fresh water) 
Gastropoda (land and fresh water) . . 
(Lamellibrancheata, few fresh water) 
Nematoda 
Oligochaeta (land and fresh water) . . 
Polychaeta (very few fresh water) 
Hirudinea (fresh water) 
Polyzoa— (few fresh water) . . 
Crustacea (fresh water and land) 
Insecta (chiefly land) 
: Onychophora 
Myriapoda 
Arachnida (chiefly land) 
Cyclostomata (few fresh water species) 
Teleostomi (fresh water) 
Elasmobranchii, rare in fresh water 
Dipno— (fresh water) 
Amphibia 
Kept ilia 
Birds . . 
Mammals 
Marine Animals. 
Protozoa 
Sponges 
Coelenterata 
Echinodermata (all groups) 
Platyhelminthes 
Nemerteans 
Rotifera 
Gastropoda 
Lamellibrancheata 
Cephalopoda 
Solenogastres 
Scaphopoda 
Nematoda 
Oligochaeta (few species) 
Polychaeta 
Hirudinea 
Archiannelida 
Echiuroidea 
Sipunculoidea 
Priapuloidea 
Phoronidea 
Polyzoa 
Brachiopoda 
Chaetognatha 
Crustacea (i chiefly marine) 
Insect a (very rare indeed) 
Arachnida (very few examples) 
Tunicata 
Enteropneusta 
Cephalochordata 
Cyclostomata 
Teleostomi 
Elasmobranchii 
Reptilia 
Birds (at least adapted to life on sea) 
Mammals 
