64 THE MICROSCOPE. 



becomes changed into formed material, while fresh nuclei 

 .and nucleoli are developed. And so far from nuclei being 

 formed first, and the other elements of the cell deposited 

 around them, they always make their appearance in the 

 substance of pre-existing matter, and have neither a 

 -different constitution to ordinary germinal matter, nor 

 perform any special function. 



Of the Increase of Cells. Several distinct modes of cell- 

 multiplication have been described, but in all cases the 

 germinal matter divides, and is the only material actively 

 concerned in the process ; which may, however, take place 

 in different ways. 



1. The parent mass may simply divide into two equal 

 parts, apparently in obedience to a tendency of the por- 

 tions to move away from each other as soon as the original 

 mass has reached a certain size. 



2. The parent mass may divide in three, four, or more 

 equal portions. 



3. From every part of the parent mass protrusions may 

 occur, each of which, when detached, absorbs nutrient 

 matter, and soon attains the same size as its parent. 

 During these processes of increase and multiplication, the 

 formed material is perfectly passive, and when a septum 

 or partition exists, it does not result from a " gro wing-in" 

 of this dead structure, but is produced by the conversion 

 of part of the germinal matter into a thin layer of formed 

 material. 



Of tlie Changes of the Cell in Disease. If the conditions 

 under which cells ordinarily live be modified beyond a 

 certain extent, a morbid change may result. For instance, 

 if cells, which normally grow slowly, be supplied with an 

 excess of nutrient pabulum, they grow that is, convert 

 certain of the constituents of the pabulum that come into 

 contact with them into matter like themselves at an 

 increased rate. In this way the inflammatory product 

 pus results. " The abnormal pus-corpuscle may be pro- 

 duced from the germinal or living matter of a normal 

 epithelial cell, tlie germinal matter of which has been supplied 

 with pabulum much more freely than in the normal state" 

 In cells in which the access of nutrient pabulum is more 

 restricted tlian in the abnormal state, as in normal cells 



