TISSUES, ORGANS, AND SYSTEMS. 91 



of the connective tissue, when once formed, grow in length and thick- 

 ness like the elastic fibres, until they have attained the size which they 

 possess in the adult ; however, there arise subsequently, in many places, ' 

 additional elements, which are combined with the original ones. The 

 perfect connective tissue, when unmixed, is almost non-vascular, and with 

 regard to nutrition, it is certainly very low in the scale, whence it 

 undergoes hardly any morbid changes. The vascular connective tissue 

 is an exception to this rule, but the changes in this case depend not 

 upon any .peculiarity in the connective tissue itself, but are determined 

 by the vessels, fat-cells, &c., contained in it. The bundles of fibrils of 

 the connective tissue and the elastic fibres stand at the bottom of the 

 series of the higher elementary parts, and thence most readily adapt 

 themselves to the regeneration of lost substance, or to the increase of 

 parts which already exist. 



The union of the different elements of the connective tissue is effected 

 in many ways, but the following forms are most worthy of distinction : 



1. Solid connective tissue (formed connective tissue, Henle). In this 

 the elements are intimately united, and in such a manner, that simple 

 organs of well-marked form proceed from them. To this belong: 



a. The tendons and ligaments, with parallel bundles, united by loose 

 connective tissue into larger cords, between which a relatively very 

 small number only of fine elastic fibres, and fibrous networks, pene- 

 trate. 



b. The fibro- cartilages have the same structure as the tendons and 

 ligaments, but with numerous scattered cartilage cells, and without finer 

 elastic fibres. They exist either as special organs, such as the cartila- 

 gines inter articular es and the cotyloid ligaments, or in particular parts 

 of other organs composed of connective tissue, especially in the tendons, 

 the tendinous sheaths, and the ligaments. 



c. The fibrous membranes are distinguished from a, only by the fre- 

 quent interweaving of the bundles, and generally by the more considera- 

 ble number of the elastic fibres. Here may be enumerated : 



1. The muscular fascia?, which have more the structure of tendons. 



2. The periosteal membranes and the perichondrial membranes, con- 

 taining sometimes a great number of elastic elements. 



3. The white dense tunics of many soft organs, as the dura mater, the 

 neurilemma, the sclerotic and cornea, the fibrous coat of the spleen and 

 kidneys, the tunica albuginea of the ovaries and testes, penis, and 

 clitoris. In the last-mentioned parts, and in the spleen, these coats, 

 which consist of a solid connective tissue and numerous fine elastic fibres, 

 are continued into the interior, where, mixed to some extent with smooth 

 muscles, they constitute a more or less complete framework, which 

 appears in the form of partitions, or of a stroma, or of a trabecular net- 

 work. In the cornea we find a modification, inasmuch as the connective 



