164 THE LIVING WORLD. 
the immediate link between the Dicynodon and crocodile of the present period, 
as the illustration shows. Its length was about thirty feet. 
From the saurian creatures above described the crocodile and alligator 
descended, diminished in size in consonance with the changes which time has 
beeoddn RESTORED (from the tn'as). 
wrought, as already explained. Though smaller than their ancestors, and 
modified materially in aspect, they are still the most formidable of amphibians, 
being quite as dangerous in the water as the tiger is on land. 
The Crocodile. In the ancient species described we find them all 
provided with paddles instead of feet, because there was little land in 
existence during the secondary period, and 
even the land that was formed had not yet 
begun to be prolific with plant life. But the 
land gradually encroached upon the water, 
the temperature became lower, and vegetation 
sprang up while animal life increased rapidly 
along the newly formed shores. This change 
was followed by others equally pronounced 
in the animal world, for the saurians gradu¬ 
ally exchanged their paddles for feet; or to 
be more definite, the saurians of the second¬ 
ary period, finding their feeding grounds 
growing less, in their unappeased voracity 
fell to devouring each other, while many 
others were caught in pools and being un¬ 
able to effect their escape across land into 
deeper water perished as the pools dried 
up. Thus from several causes the last of 
the mighty creatures, whose fossil remains we 
now study with so much interest, became 
extinct, but were succeeded by their milder congeners which the Creator pro¬ 
vided with feet instead of flippers, and thus adapted them to conditions corn- 
portable with the regions in which they were appointed to live. 
The True Crocodile. This reptile is peculiar to the Nile river, where, 
THE MYtOBON. 
