THE CELL 25 



bits of the nucleus will continue to live and what 

 is more will gradually reconstruct themselves so 

 that each of them will become a new organism. 

 But not so the bits which have not been fortunate 

 enough to secure a fragment of nuclear substance. 

 As above stated these portions linger for a time 

 with some of the signs of life but ultimately die. 



Hence we may conclude with Balbiani 1 that 

 " the cellular life neither resides exclusively in the 

 protoplasm [i.e., cytoplasm or cell-protoplasm as 

 opposed to nucleoplasm] nor within the nucleus, 

 but results from the reciprocal relations which are 

 established between these two elements. Isolated 

 one from the other, neither of them is capable of 

 life by itself." 



The various structures which have thus briefly 

 been passed under review are the main constituents, 

 not only of the unicellular organism, but also of all 

 living cells, whether they be gland, nerve, muscle or 

 bone cells. Each of these specialised cells, how- 

 ever, has its own peculiar powers and duties and 

 its own characteristic features. In addition to the 

 structures mentioned, a cell may contain fatty 

 substances, vacuoles or cavities containing fluid 

 and even crystals. 



Having now studied the appearance of the cell 

 as it presents itself to us under the microscope it 

 1 Annales de Micrographie, 1893. 



