Scientific Lectures. 153 



Washington, l!^ew Brunswick, and Albany, and ultimately of Phila- 

 delphia, where I found that there were a series of bones, such as I 

 desired. I found that they had rich treasures in fossils, though they 

 were in dark cases, and not to be discerned or understood by the 

 public. The members of the curators and trustees of the Academy 

 at Philadelphia most cordially and liberally allowed me the full use of 

 those fossils, in consideration, of course, that it was a national work 

 in which I was engaged, and on behalf of the commissioners of the 

 Central park of your city. I examined those treasures, and found 

 them to consist of these large bones ; the thigh bone, which is forty- 

 one inches in length, and the tibia and the fibula, the two bones of 

 the lower leg, and two bones of the foot, and a small piece of the 

 pelvis, which was in several fragments. These dark castings were 

 taken from the fossils. I received permission to make the molds and 

 castings on condition of leaving the molds in possession of the aca- 

 demy. The commissioners very liberally consented to that arrange- 

 ment; and as soon as I got all I could get from that source, I 

 proposed to place the bones I have named, and which are here of a 

 darker color, in their natural position with my models of the bones 

 that were not there, and so erect the whole skeleton at my own 

 expense for the academy of Philadelphia, in acknowledgment of the 

 liberal treatment I had received from them in facilitating my work 

 for the Central park. After some difficulties I succeeded in com- 

 pleting it on the 17th of IITovember last, and I presented it to the 

 trustees and curators, who gave me an agreeable recognition of the 

 fact of my having rendered that which up to that time was hidden 

 science, popular, for the benefit, I trust, of the people, and especially 

 of the young folks rising up, who will ultimately be as familiar with 

 the giants of those ancient times as we are with the cattle of our 

 present period. 



Now, I will ask you to remember what I said with reference to 

 the tail of the crocodile. You will see that these suggestions are here 

 actually realized. There is the arch inverted to protect the large 

 blood-vessel, because that creature had to use the tail by pressing it 

 upon the ground to help him in keeping that erect position. Had 

 there not been such provision as that, the circulation of the blood 

 would have been seriously impeded. Hence you see the wonderful 

 adaptation of that one plan, shown in the bird, which has not, except 

 in rare instances, a long tail formed of bones, and in this reptile 

 which has. These long spines, which are in some degree like those 



