696 A CENTURY OF PROGRESS IN THE NATURAL SCIENCES 



of the coal measures. In 1847 James D. Dana attributed the folding to horizon- 

 tal compression of the strata as the result of the slow cooling and contraction of 

 the earth's nucleus. 



The foundations of Tertiary stratigraphy and invertebrate paleontology in 

 North America were established by the investigations of T. A. Conrad with a 

 series of contributions commencing in 1832 and continuing to and beyond 1850. 

 The more important of his earlier papers included descriptions and illustrations 

 of the Eocene shells of Alabama, the medial Tertiary fossils of the Atlantic 

 Coast, and studies of fossils collected by W. P. Blake in California, as well as 

 those obtained by the Wilkes Exploring Expedition near the mouth of the 

 Columbia River at Astoria, Oregon. Many of these contributions were pub- 

 lished in the American Journal of Science, the Journal of Conchology, and the 

 Proceedings of the PMladelpJiia Academy of Sciences. The visit of Sir Charles 

 Lyell to America in 1844 rendered possible a comparison of the Tertiary de- 

 posits with those of Europe. 



Reseakch and Publication Facilities Prior to 1850 



The earlier contributions to paleontology and historical geology in Europe 

 were largely by men who were sponsored and financed by those in control of 

 state governments or by financially independent individuals interested in scien- 

 tific work. After the private publication of William Smith's geological map of 

 a part of England the value of geological work by the state became apparent. 

 The Geological Survey of the United Kingdom was founded in 1835 under the 

 direction of de La Beche and about the same time preparations were begun for 

 a geological map of France. In North America the State Geological Survey of 

 North Carolina was established in 1823, other states following this example, South 

 Carolina in 1824, and Tennessee in 1831, while the Canadian Geological Survey 

 was founded in 1841. The universities in Europe have always taken an impor- 

 tant part in advancing the sciences of paleontology and historical geology and 

 in training future investigators. Collections of fossils, together with library fa- 

 cilities, rendered possible the comparison of materials gathered from various 

 parts of the world. Toward the middle of the nineteenth century geologists and 

 paleontologists established professional organizations which provided scientific 

 meetings, where the results of investigations could be presented and discussed, 

 as well as facilities for publication. The Geological Society of London was or- 

 ganized in 1807 and the Palaeontographical Society of London in 1847. Impor- 

 tant monographs on both invertebrate and vertebrate fossils began to appear in 

 1847 in the German publication Palaeontographica. The Geological Society of 

 Germany was founded in 1849 and in it have appeared many important contri- 

 butions to the geology and paleontology of Europe and other parts of the world. 



Invertebrate Paleontology 1850-1950 



At the beginning of the second half of the nineteenth century the theory of 

 the immutability of species, together with the idea of special creation, had been 

 strongly challenged by an increasing number of scientific investigators. Many 

 important papers and monographs had been published with descriptions and il- 



