WHAT IS A CELL. 



53 



nected with it, showing that, as in tendon, the germinal 

 matter passes uninterruptedly into the formed material. In 

 the formation of the contractile tissue, the germinal matter 

 seems to move onwards, and at its posterior part gradually 

 undergoes conversion into tissue. At the same time it 

 absorbs nutrient material, and thus, although a vast amount 

 of contractile tissue may have been produced, the germinal 

 matter which formed it may not have altered in bulk. 

 PL VII, fig. 25. The fibres of yellow elastic tissue are 

 formed in the same manner, and each fibre is thickened by 

 the formation of new material from germinal matter, which 

 lies upon the external surface of each fibre, fig. 26. 



The Formation of Nerve Fibres. 



The nerve fibre is composed of formed material, which 

 is structurally continuous with the formed material of the 

 nerve cells of the nerve centres. A nerve fibre at an early 

 period of development consists of a number of oval masses 

 of germinal matter linearly arranged. As development 

 proceeds, these become separated farther and farther from 

 one another, and the tissue which is thus spun off as they 

 become separated, is the nerve. PI. VII, fig. 27. 



What is essential to the Cell ? 



All that is essential to the cell or elementary part is 

 matter that is in the living stake germinal 'matter, and 

 matter that has been in the living state -formed material. 

 With these is usually associated a certain proportion of 

 matter about to become living the pabulum or food. So 

 that we may say that in every living thing we have matter 



