ESSENTIAL TO A CELL. 



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What is essential to constitute a Cell? It has been shown 

 that what is essential to the cell or elementary part is r 

 matter that is in the living state bioplasm, and matter that 

 has been in the living state formed material* With these is 

 associated a certain proportion of matter in solution, and, 

 therefore, not visible, but which is about to become living 

 \hr.pabulum or food. So that we may correctly say that in 

 every living thing we have matter in three different states 

 j, matter about to become living; 2, matter actually living; 

 and 3, matter that has lived. The last, like the first, is non- 

 living, but unlike this it has been in the living state, and has 

 had impressed upon it certain characters which it could not 

 have acquired in any other way. By these characters we 

 know that it has lived, for we can no more cause matter to 

 artificially take the characters of the dried leaf, the lifeless 

 wood, shell, bone, hair, or other tissue, than we can make 

 matter take the living state in our laboratories. " Cells " in 

 different forms are represented in Pis. I, II, IV, V, VI, 

 VII, VIII. 



Of Fibrous and other Tissues. The structure of other 

 tissues may be represented in the simple way already 

 described. At no period of their existence, in most cases, 

 will any of the characters formerly assigned to the " cell " 

 be discovered. If we examine a piece of ordinary tendon 

 (sinew) one of the lowest of the tissues, which has been 

 properly prepared for examination, we shall find that the 

 so-called " nuclei " or " nuclear fibres " are composed of 

 bioplasm, and constitute the growing and only living part 

 of the tissue, while the so-called " intercellular substance " 

 or tendinous tissue which intervenes is the formed material 

 which has been formed by them. By careful tearing the 



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