94 



the microscope, that they were, in the slightest degree, allied to each 

 other. 



The several portions of this substance in my possession, differ from 

 each other in some respects in reference to their external characters, 

 though in their composition all are alike. Some of the portions are 

 in the form of riband-shaped masses, of which the largest is six inches 

 in length, varying from half to three quarters of an inch in breadth, 

 and is about a line in thickness, (Plate xi. fig. 1) : there are five or 

 six portions of similar breadth and thickness, and varying from one to 

 two inches in length. These portions are highly elastic, and may be 

 stretched to a considerable length, returning again to their former 

 shape with considerable resiliency. This elasticity however is chiefly 

 observed when the pieces are stretched in the longitudinal direction, 

 as they are capable of very little extension transversely. The margin 

 of some of these portions is irregular and flocculent, being formed 

 evidently of minute filaments, and resembling the villous surface of a 

 mucous membrane, and in the largest piece the whole surface has this 

 velvety appearauce. Others of these portions present more distinct 

 evidences of a fibrous arrangement, (fig. 4), and distinct traces of fi- 

 bres, or, as they will be presently shown to be, bundles of filaments, 

 may be observed extending through the mass, both longitudinally and 

 transversely, but the surface or the margins still preserving a floccu- 

 lent appearance. One or two of these pieces, of which the border is 

 nearly smooth, present very much an appearance of having been cast 

 in a flattened or contracted portion of the small intestines ; one of 

 these especially (fig. 3), which is only four lines in width, looks like 

 a portion of the intestine of some small animal, with its mucous mem- 

 brane turned externally and flattened, but, like the other portions, it 

 is not hollow, but riband-shaped. The remaining portions differ 

 from these only in presenting no trace of the flocculent surface or mar- 

 gins, and in being more completely membranous. They might, in 

 fact, be easily mistaken for portions of animal membrane, and being 

 of a closer texture have much less elasticity than the former portions. 

 The thinnest of these portions, which at its edge is nearly diapha- 

 nous, is very smooth and shining, having almost a tendinous lustre. 

 To the naked eye it appears to be made up of fibres, both longitudi- 

 nal and transverse, but the longitudinal prevail, and the mass more 

 readily splits in that direction, the splitting taking place with a clean 

 margin, as if cut with a sharp instrument. This fragment bears no dis- 

 tant resemblance to a piece of dura mater, covered by the arachnoid 

 membrane (fig. 2) ; both surfaces are equally smooth, and no appear- 



