THE HORSE 



E. 



Age. 

 Palaeolithic 



or 

 Post-Tertiary 



or 

 Quaternary or 

 Pleistocene 



Period. 



{Upper, or Post-Glacial 

 Pleistocene 



( Middle, or Last Glacial 



\ Pleistocene 



Lower Pleistocene 



Age of the Reindeer, and the 

 artistic Reindeer Men. 



Hipparion assumed complete 

 form of horse. 



Age of the Neander Men. 



Mild climate. Age of the 

 Hippopotamus in England, 

 and other European rivers. 



D. 



C. 



Pliocene 



r Upper 



Lower 



(Tertiaries. Miocene ... 

 Advent of Oligocene . . . 

 Mammals Eocene 



Plio-hippus, extra digits en- 

 tirely rudimentary. 



Hipparion three-toed. About 

 the size of a Shetland pony. 



American " Anchitherium." 



Stripes and spots appear. 



Eo-hippus, New World. 



Hyracotherium, Old World, 

 four-toed, probably foxy- 

 red in hue, and about 

 eleven inches high. 



Phrenacodus, the five-toed, 

 earliest hoofed mammal 

 yet discovered. 



Chalk Age 



C Secondary Jurassic 



or 

 •< Mesozoic. 

 I Age of 

 1^ Reptiles 



Triassic 



Fossil shells, and birds found 

 in America possessing 

 teeth. 



Advent of first bird. Flourish- 

 ing period of Ammonites, 

 and Reptiles, such as the 

 Icthyosaurus, Deinosaurus, 

 Pleisiosaurus. 



B. 



Primary 



Age of Fishes 

 and MoUusks 



Permian 



Carboniferous (Coal Mea- 

 sures) 



Devonian 



Silurian 



Cambrian 



Formation of Limestone, 



Slate and Sandstone. 



Reptiles began to crawl. 

 Great Forests, and profuse 



plant-life. 

 True sharks, and Ganoid 



fishes. 

 Plant-like animals, and small 



fishes. 

 Age of trilobites. 



A. Pre-Cambrian Torridonian Sandstone 

 and various igneous 

 rocks 



No undoubted fossils yet 

 found, but probably existed, 

 as the chief genera of inver- 

 tebrates are found in the 

 Cambrian. 



develop the numerous groups that now exist, specialised 

 for the particular duties for which they are required. In 

 this the breeders in the British Islands have taken a fore- 



