Nov. 1S47.] 313 



Haldeman, was read and referred to a committee consisting 

 of Dr. Griffith, Dr. Wilson, and Mr. Phillips. 



Dr. Leidy made the following remarks upon the very slow 

 destrnctibility of animal tissues in certain states. 



The great length of time that animal matter may be preserved 

 in a recent form, in ice, is so well known as hardly to need refe- 

 rence to the instance of the Siberian mammoth. 



Bones and teeth, under ordinary circumstances, resist the in- 

 fluence of exterior agencies better than any of the other tissues, 

 and then follow epidermic tissue, 6brous tissue, &c. Bones of the 

 mastodon have long since been determined to contain almost as 

 much gelatin as those of recent animals, and I have lately detect- 

 ed, by chemical analysis, the existence of animal matter in a por- 

 tion of a vertebra of the Basilosaurus, a fossil of the Eocene tertia- 

 ry period. A portion of this animal matter, preserved in alcohol, 

 I exhibit to the Academy. It has a flocculent appearance, con- 

 tains no gelatin, but readily carbonizes and takes fire, giving out 

 an odour characteristic of burning animal substances; the ash it 

 leaves behind contains a large proportion of oxide of iron. 



If not exposed to the influence of air and moisture, bones will 

 retain their animal matter for an indefinite period of time. We 

 have, in the collection of the Academy, bones of the extinct 

 Megalonyx, from White Cave, Tennessee, which look as fresh as 

 though prepared but yesterday. But when they are exposed to 

 air, and to alternations of dryness and moisture, or a constant but 

 slightly moistened state, without the presence of carbonate of 

 lime, silex, or oxide of iron, which tend rather to the preserva- 

 tion than destruction of the animal matter contained in them, the 

 auimal matter is gradually and almost wholly removed, leaving 

 nothing but the earthy constituents, which, if they do retain the 

 original form, readily crumble to pieces from the slightest vio- 

 lence. Of the softer animal tissues, the preservation of insects 

 in amber, a resin belonging to a very ancient flora, is well 

 known. But one of the most remarkable instances occurring 

 under ordinary circumstances, which has been presented to my 

 notice, is the existence of portions of fibrous membrane and 

 articular cartilage, attached to some of the bones of the Megalonyx 

 before spoken of, as exhibited in these specimens. By ex- 

 amining this piece of fibrous membrane, taken from one of the 

 bones, it will be found to have retained all the characteristics of 

 perfectly recent membrane ; it imbibes moisture and becomes as 

 flexible as if fresh. The articular cartilage has become hard and 

 brittle and yellow in colour, and looks like resinous matter. A 

 fragment beneath the microscope presented all the characters of 



