THE FROG 



It is a mistake to think that only human beings have 

 family trees. Frogs — all animals — have them too, only we 

 think of their tree not as made up of generations, but of a 

 series of species or forms that have gone before in very ancient 

 times. The most interesting thing about the frog is that his 

 ancestors, way down at the root of his family tree, helped to 

 bridge the gap between the water and the land animals. 

 This was really a wonderful achievement, and, to this day, 

 the frog in his development keeps repeating the feat, which 

 is no less wonderful than in the first frogs. These ancient 

 frogs were also the first back-boned animals to acquire hands 

 and feet with fingers and toes. They were the first to crawl 

 out of the water upon the land, and to breathe with lungs 

 instead of gills. Every frog which reaches maturity repeats 

 again the story of his race in his earlier stages, harking back 

 as a tadpole to the simpler life in the water, and as adult liv- 

 ing the life of the higher land animals. 



The Race for the Land 



Nature is in great haste to turn the tadpole into the frog. 

 Why? The rapid drying of the shallow ponds and pools in 

 which frogs and toads lay their eggs would result in the death 

 of the tadpoles if they had not already changed to frogs and 

 were ready to breathe air and climb out upon the land. 



Toads usually lay their eggs in shallow ditches and pools 

 of the open fields. Their life from egg to diminutive toad is 

 only a matter of six or eight weeks. It, therefore, matters 

 little to them that the pools dry up quickly, since, as adults, 

 they are practically land animals anyway. The common 

 frog, however, requires three months or more to mature, and 

 the bullfrog, whose eggs are laid in the deeper water of the 

 marshland, does not make the change until the second, or 

 even the third, year. 



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