Prof. Hitchcock on Ichnolitliology , or Fossil Footmarks. 309 



If this coprolite be examined with a glass, small black grains 

 may be seen in some parts, which resemble small seeds, and 

 which one cannot but strongly suspect to be seeds, that passed 

 undigested through the animal. I have not been able to deter- 

 mine this point certainly, from having so small a quantity of the 

 substance. But it strongly confirms the above suggestion, that 

 the same conclusion was made by Dr. Samuel L. Dana, to whom 

 I sent a small fragment for another purpose, as will appear in the 

 sequel, though I said nothing to him of the seeds. I quote his 

 remarks on the subject. " I want to say a word about the Mack 

 grains, &c., in the coprolite. In the unbroken bit, about as big 

 as a hazle nut, I think I can discover an evident tendency to con- 

 volution ; so that these black masses would, if the thing could 

 be unrolled, lie for the most part in the same plane, though in the 

 interior of the bit the black grains are more promiscuous. I call 

 these grains ; for, if you examine them, they nearly all approach 

 the form of an apple seed. They may be raised out of the little 

 shell of carbonate of lime, sometimes crystalline, which surrounds 

 each. Others have the form of stems. The black matter of 

 these grains is carbonaceous. They consist, when that is burned 

 off, of phosphate and carbonate of lime. Now allow me a word 

 of speculation. I cannot but think these black grains are seeds, 

 which have passed undigested through the intestines, and have 

 assumed, in the passage, such position as these foreign bodies 

 would, and often do, in the feces." 



The external characters of these nodules corresponding so 

 nearly to those of coprolites, I felt a strong desire to have them 

 subjected to a most thorough and careful analysis. Some years 

 ago, when I suspected that I had found some coprolites with the 

 footmarks, Dr. Dana suggested to me, that, if dropped by birds, 

 they might contain uric acid. This thought seemed to me wor- 

 thy of being pursued ; and since I had the highest opinion of 

 Dr. Dana's analytical skill, I requested him to undertake the ex- 

 amination of this substance, with the suggestion respecting uric 

 acid in mind. He consented, and after bestowing a great deal of 

 time and labor upon the subject, he has presented me with some 

 of the most unlooked for and beautiful results that I have ever 

 seen derived from chemical analysis. Dr. Dana's earlier results 

 gave — 



Vol, xLvii, No. 2.— July-Sept. 1844. 40 



