188 CONNECTIVE TISSUE. [BOOK i. 



which is generally solid, and is commonly spoken of as matrix. In 

 most forms of connective tissue the matrix is relatively so abund- 

 ant and prominent, that the cells, or connective tissue corpuscles 

 as they are called, become inconspicuous ; and, speaking generally, 

 the value of connective tissue to the body depends much more on 

 the qualities of the matrix than on the activity of the connective 

 tissue corpuscles. 



The kind of connective tissue, sometimes called " loose connec- 

 tive tissue," which wraps round and forms a bed for the blood vessels, 

 consists of an irregular meshwork formed by interlacing bundles of 

 various sizes which leave between them spaces of very variable 

 form and size, some being mere chinks or clefts, others being larger 

 but generally flattened passages, all containing lymph and having 

 as we shall see special connections with the lymphatic vessels. 

 The larger spaces are sometimes called "areolse," and this kind of 

 connective tissue is sometimes spoken of as " areolar tissue." 

 When a small portion of this tissue is teased out carefully under 

 the microscope, the larger bundles may be separated into finer 

 bundles, and each bundle, which generally pursues a wavy course, 

 has a fibrillated appearance as if made up of exceedingly fine 

 fibrilla^ ; treated with lime water or baryta water the bundles do 

 actually split up into fine wavy fibrillse of less than 1 p in diameter, 

 a substance of a peculiar nature which previously cemented the 

 fibrillse together being dissolved out from between them. When 

 a mass of such fibrillse is boiled with water, they become converted 

 into gelatine, a substance containing, like proteid material, carbon, 

 nitrogen, hydrogen and oxygen with a small quantity of sulphur, 

 but differing from proteid material both in its percentage compo- 

 sition and in its properties. A remarkable and well known feature 

 of gelatine is that its solutions while fluid at a temperature of 

 boiling water or less, become solid or a 'jelly' at lower tempera- 

 tures. The untouched fibrillas, in their natural condition, behave 

 as we shall see in speaking of the digestion of connective tissue, 

 somewhat differently from prepared gelatine ; the natural fibrilla 

 therefore, does not consist of gelatine but of a substance which by 

 boiling is readily converted into gelatine. The substance soluble 

 in lime or baryta water, which cements a number of fibrillae into 

 a bundle, appears to be allied to a body, of which we shall speak 

 later on, called mucin. Since the fibrilla form by far the greater 

 part of the matrix of connective tissue, a quantity of this tissue 

 when boiled seems almost entirely converted into gelatine. 



In connective tissue then a number of exceedingly fine gelati- 

 niferous fibrillte are cemented together into a fine microscopic 

 bundle, and a number of these finer bundles may be similarly 

 cemented together or simply apposed together to form larger 

 bundles; some of the bundles at least appear moreover to be defined 

 by a delicate transparent sheath of a somewhat peculiar nature. 

 A number of these bundles, small and large, are arranged as a 



