These and many other varieties of snail 

 fossils are distributed through the rocks 

 in Slavonic as if they were descended 

 from common ancestors. Forms (b) and 

 (d), for example, resemble (a) more than 

 one another; (c) is more like (b) than 

 any of the others; (e) is more like (d); 

 and soon. Fossils resemble most closely 

 those in the nearest layers above or 

 below. If we should find these forms 

 scattered over widely separated areas, 

 experts would undoubtedly consider 

 them as distinct species. Only one 

 reasonable explanation has been sug- 

 gested for the distribution of these shells 

 in the various layers and in the regions 

 of the entire area, and that is that 

 descendants have come in time to differ 

 more and more from their ancestors 



After Neumayr 



DIVERGENCE RELATED TO TIME 



Refrigerated Fossils Paleontologists and morphologists had reported 

 the ancient existence of mammoths, animals supposed to resemble the ele- 

 phants of India, but having shaggy wool and very long, slender and curled 

 tusks. But nobody had ever seen such an animal. There were indeed pictures 

 of such animals on the walls of caves in France, made presumably by pre- 

 historic man (see illustrations, page 57). Scientists inferred the former 

 existence of this type of animal from fossils picked up from time to time in 

 various parts of northern Europe and northern Asia. They inferred a great 

 deal about the size, the form, the mode of life of this animal. For many cen- 

 turies the natives in parts of Siberia had made quite a business of digging up 

 bits of the tusks and selling them to the Chinese, who made carved ivory orna- 

 ments of them. But nobody had ever seen a mammoth. There had been no 

 "history" or tradition to tell us of such animals. 



u Early in this century Russian explorers in northeast Siberia found buried 

 under many feet of ice a complete mammoth. This animal had apparently 

 fallen into a crack in the ice, had been covered by snow, and had been frozen 

 solid. So well preserved was this animal that the blood in the veins and arteries 

 could be thawed out. The contents of the stomach could be identified as made 

 up of grasses and other plants of the region. And when the flesh was thawed 

 out, it was eaten by the dogs. Since then, some two dozen more such per- 

 fectly preserved mammoths have been found in the frozen swamps. 



Interpreting Fossil Facts^ Some strange petrified bones that had been 

 dug up from under the streets of Paris were brought to Georges Cuvier. At 



iSee No. 2, p. 470. 

 454 



