AMERICAN MUSEUMS 35 



Extinct Forms of Life. 



Four other rooms are also being prepared to exhibit the 

 geological succession of animal life. In the first room the 

 visitor will find illustrations of the mollusca, the trilobites, 

 and the strange and often gigantic fishes of the palaeozoic 

 era down to the Devonian age. The next will contain the 

 same groups as exhibited in the Carboniferous period, 

 with the earliest forms of amphibia and reptiles, and their 

 later developments in the Jurassic period when the first 

 small mammals made their appearance. Here will be 

 exhibited models of the huge reptile (Atlantosaurus) dis- 

 covered by Professor Marsh, by far the largest of all 

 terrestrial animals. Then will come a room devoted to the 

 Cretaceous deposits, the wonderful giant Ammonites, and 

 the abundant reptilian and bird forms which have been 

 discovered in America. The last room of the series will 

 be devoted to the Tertiary deposits, and will show the 

 many curious lines of modification by which our most 

 highly-specialized animals have been developed. If some 

 of the preceding rooms contain the most marvellous pro- 

 ducts of remote ages, here assuredly will be the culminat- 

 ing point of interest in seeing the curious changes of form 

 by which our existing cattle and horses, sheep, deer, and 

 pigs, our wolves, bears, and lions, have been gradually 

 modified from fewer and more generalized ancestral 

 types. 



Of all the great improvements in public museum- 

 arrangement which we owe to the late Professor Agassiz 

 and his son, there is none so valuable as this. Let any 

 one walk along the vast palseontological gallery at South 

 Kensington, and note the crowded heaps of detached bones 

 and jaws and teeth of fossil elephants and other animals, 

 all set up in costly mahogany and glass cases for the 

 public to stare at, with here and there a more complete 

 specimen or a restoration ; but all crowded together in 

 one vast confusing series from which no clear ideas can 

 possibly be obtained, except that numbers of strange 

 animals, which are now extinct, did once live upon the 



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