CONNECTIVE TISSUES ELASTIC TISSUE. 



65 



stitute the walls of tubes or cavities having free outward communication. 

 The interspaces between the fibres of connective tissue are believed by many 

 to constitute the commencement of the lymphatic system, receiving the 

 superfluous material poured out by the bloodvessels for the supply of the 



FIG. 23. 



FIG. 24. 



Caudal Tendon of young rat, showing the ar- 

 ra'ngement, form, and structure of the tendon 

 cells. 



Transverse section of Tendon, showing branched 

 cells, inclosing spaces which, here left blank, are 

 naturally filled with tendinous fasciculi. 



several textures, and gradually conveying it, at first through irregular spaces 

 partially filled with protoplasmic masses or cells, but subsequently through 

 proper tubes, to the thoracic duct, from whence it is again discharged into 

 the blood. On boiling with water this tissue yields gelatin. 



The mode of development of connective tissue has been much elucidated 

 by the recent researches of Rollett, 1 Boll, 2 and others. It seems to be ascer- 

 tained that, as Schwanu originally maintained, the primary cells of the 

 tissue become greatly elongated and slightly branched, and their protoplas- 

 mic substance assumes a finely fibrillated aspect ; at the same time, however, 

 in various forms of connective tissue, as in the peritoneum for instance, the 

 intermediate homogeneous matrix, as was strongly maintained by Virchow, 

 Bonders, and others, also undergoes fibrillation, the bundles thus formed 

 constituting the fasciculi of fibrils of the fully-developed tissue. The elastic 

 fibres are commonly believed to be the result of a direct deposit, or differ- 

 entiation of the matrix, though Virchow thought they were the remains of 

 the cells. Besides the cells which become fusiform and fibrillated, connec- 

 tive tissue always contains wandering cells. 



45. ELASTIC TISSUE. The elastic tissue that we have just seen to be 

 mingled in small quantity with white fibrous tissue in situations where it is 

 requisite that the latter should accommodate itself to changes of form, bulk, 

 or position in the organs it invests, is sometimes met with in an almost pure 

 state. In the vocal cords and the ligamenta subflava good examples are 

 seen of this tissue, with scarcely any intermixture of white fibrous tissue. 

 In the ligamentum nuchre and the suspensory ligament of the penis, in the 

 stylo-hyoid, thyro-hyoid, and crico-thyroid ligaments, and in the coats of 

 the bloodvessels and lymphatics, both kinds of tissue are present in nearly 

 equal proportion, though perhaps the elastic predominates; whilst in the 

 subcutaneous and submucous areolar tissue, the elastic fibres, though numer- 



1 Strieker's Manual of Histology, Syd. Soc. Transl., 1870, p 84, where the student 

 will find a resume" of all modern views up to that date. 



2 Archiv f. Microscop. Anatomie, Band vii, p. 28, 1871, which article also con- 

 tains numerous references. 



