SIMPLE FIBROUS TISSUES. 



119 



observed in all of them. We must not mistake for the absence of coagu- 

 lating power, the remarkable retardation of the act of coagulation which 

 sometimes occurs. Thus, the blood is occasionally found in a fluid con- 

 dition in the bodies of persons that have been dead for some days ; and 

 yet when withdrawn from the vessels, it coagulates. 



2. Of the Simple Fibrous Tissues. 



188. A large part of the Animal fabric, especially among the higher 

 classes in w r hich the parts have the greatest amount of motion upon one 

 another, is composed of tissues, which seem as if they consisted of 

 nothing else than fibres, of the simple character already described, 

 woven together in various ways, according to the purposes they are 

 destined to serve. These fibres are altogether different from those 

 hereafter to be described as constituting the Muscular and Nervous tis- 

 sues, and must not be confounded w T ith them. The former are solid, 

 and possess none but physical properties ; the latter are tubular, and 

 are distinguished by their peculiar vital endowments, which seem chiefly, 

 if not entirely, to reside in the contents of the tubular fibre. The Sim- 

 ple Fibrous tissues, of which we have now to freat, appear to have it for 

 their sole office in the animal body to bind together the other elementary 

 parts into one whole, without uniting them so closely as to render them 

 immovable ; and we find the same elements arranged in very different 

 modes, according to the purposes they are destined to fulfil. Thus in 

 the Tendons, by which the muscles are connected with the bones, and 

 impart motion to them, the only property required is that of resisting 

 strain or tension in one direction ; and in these we find the fibres dis- 

 posed in a parallel arrangement, passing continuously in straight line 

 between the points of attachment. In the Ligaments which connect 

 the bones together, and which also have for their purpose to afford 

 resistance to strain, but which are liable to tension in a greater variety 

 of directions, we find bundles of fibres crossing each other according to 

 these directions ; and in some instances we find the ligaments endowed 

 also with a certain degree of elasticity. The structure of the strong 



Fig. 4. 



HI 



Simple fibrous tissue; a, fibres of areolar tissue; b, tendinous fibres. 



Fibrous Membranes, which form the envelopes to different, organs and 

 bind together the contained parts, is very similar ; each of these mem- 

 branes being composed of several layers of a dense network, formed by 



