226 YELLOW ELASTIC TISSUE. 



bioplasm may be seen to pass into, or to be continous with, 

 an imperfectly formed transparent material, now soft and 

 easily broken down, but destined to gradually undergo con- 

 densation, and other changes until it shall become the firm, 

 unyielding, fibrous tissue of the tendon. There is indeed 

 to be traced a gradual transition from the soft, active, 

 formless bioplasm to the firm, passive, unyielding, fully- 

 formed tendon.* 



Yellow Elastic Tissue. It has been often stated that 

 yellow elastic tissue is formed without nuclei (bioplasm), but 

 if a specimen be carefully prepared by the process I have 

 described, numerous masses of bioplasm may, as I de- 

 monstrated many years ago, be detected without difficulty, t 

 As growth takes place, each fibre of the tissue is thickened 

 by the formation of a new material by each oval mass of 

 bioplasm, which lies upon the external surface of each 

 elastic fibre. Moving along it, the bioplasm gradually, as 

 it were, spins off the material which gradually hardens, and 

 at length becomes " yellow elastic tissue." (PL VIII, fig. 3.) 

 Muscular Tissue. The structure of muscle may be 

 described in the same simple manner. In fig. 4, PL VIII, 

 are seen the so-called nucleus (bioplasm) of muscular 

 tissue, together with the formed material. As far as I can 

 ascertain, the contractile material of the muscle precisely 

 corresponds to the fibrous tissue of the tendon. It 

 exhibits transverse markings, possesses a peculiar structure, 

 and manifests for a certain time, even after its removal from 



* "The Physiological Anatomy and Physiology of Man." New 

 edition. Plates X, XI. 



f "Bioplasm," page 115. "The Physiological Anatomy and 

 Physiology of Man." New edition. Plates XII, XIII. 



