690 THE POPULAR SCIENCE MONTHLY. 



ceedings " of the Academy. The extent to which Dr. Leidy was ab- 

 sorbed in his paleontological studies, between the years 1854 and 1872, 

 may be judged by the fact that, out of seventy-two communications 

 published during that period, only thirteen were on the subjects to 

 which he had formerly devoted his attention, and these were, for the 

 most part, brief reports of verbal communications made before the 

 meetings of the Academy. 



In 1869 his memoir entitled " The Extinct Mammalian Fauna of 

 Dakota and Nebraska" appeared as the seventh volume of the jour- 

 nal of the Academy. The work, a quarto of 472 pages, illustrated by 

 thirty lithographic plates, is the result of the gradual accumulation of 

 material during twenty-three years. This elaborate work was followed 

 in 1873 by one of equal importance, under the title " Contributions 

 to the Extinct Vertebrate Fauna of the Western Territories." It 

 forms the first volume of the superb quarto reports of the survey of 

 the Territories, under Dr. Hayden, and consists of 354 pages and 

 thirty-seven plates. 



For many years after the publication of his paper on fossil horses, 

 in 1847, Dr. Leidy was almost the only American author whose at- 

 tention was given to the study of the extinct vertebrata. The won- 

 derful remains brought to light by the explorations under the direc- 

 tion of Dr. Hayden had, however, excited the interest of others, and 

 private expeditions, as well as the official surveys, had collected rich 

 stores of vertebrate fossils, in some cases from the same localities 

 whence came the material submitted to Dr. Leidy's examination. The 

 anxiety to obtain early publication of descriptions of supposed new 

 forms became so great that, in at least one instance, such description 

 was telegraphed to a learned society from the field. The dispatch was 

 published with as little delay as possible, but the paragraph contained 

 so many errors that the experiment has not, we believe, been repeated. 

 In the attempt to settle questions of priority, the published arguments 

 became so bitter and the personalities indulged in so pronounced that 

 Dr. Leidy, who had been able to refrain from taking part in the con- 

 troversy, finally withdrew from the field. With characteristic amia- 

 bility, he had remarked in the preface to his last-named work : " The 

 investigations and descriptions of some fossils from the same localities 

 have been so nearly contemporary with my own that, for want of the 

 opportunity of comparison of specimens, we have no doubt in some 

 cases described the same things under different names, and thus pro- 

 duced some confusion which can only be corrected in future." And, 

 while others were making anxious inquiries regarding dates of issue, 

 and personal bulletins were followed rapidly by bitter little notes of 

 reclamation, he placidly held to the belief that the future would 

 undoubtedly award the credit where it belonged, and withdrew to 

 resume the studies which he had prosecuted so successfully in former 

 years. The only paleontological communication of importance which 



