RUDOLPH VIRCHOW, 1821-1902, 1)53 



naniod for its connection with the cells the "cytol)ljist.'' This sub- 

 stance Avas supposed to form first the cell nucleus and tluMi the inclos- 

 ino- sheath or cell nieni])ran(\ after which a new yerni collected between 

 the nucleus and cell inend)rane. The cui-rent ideas of life were shaped 

 entirel}^ upon the theory of generatio a'ljuivoca, and for all forms of 

 life not possessing" special generative organs parentl(\ss generation had 

 to be assumed. This view^ has long since been overthrown; for the 

 ferments by Eilhard Mitscherlich, and for the vegetable parasites prin- 

 cipally by Louis Pasteur; while in the attack upon the theory of spon- 

 taneous generation of aidmal parasites Rudolf Virchow })articipated 

 with Rudolf Leukart in clearing up the develo})nient of the trichina?. 

 Spontaneous generation was assumed in the theory of the formation of 

 the cell from the l)lastema, and the subsequent formation of a new cell 

 involved a second process of the same kind. According to the prevail- 

 ing idea there were in the bodies of men and animals a group of tissues 

 nearly destitute of cells, l)ut Yirchow's proof of the presence of cells 

 ill th(> bones and cartilage, as well as of their ])ersistent presence in 

 the connective tissues, dealt a heavy l)low to the tjieory of free-cell 

 formation, and this theory collapsed completely aft(M- his researches 

 on the connective tissue and parenchymatous iiitlanunation. That 

 which had l)een known as the cytoblast, a more or less regular sul)stance 

 lying between the cells, was recognized as lifeless. In young, grow- 

 ing, and particularly in end)ryonic tissues, the cells were found to be 

 more exclusively cellular the younger the tissue, and only after the 

 tissues reached a considera])le age did the intercellular masses ap})ear. 

 These latter, according to Virchow"s theory, were not simply dejiend- 

 cnt for their formation but for their very substance upon the cells, 

 which are the only living pails, and which are formed, as experiments 

 show(xl, oidy from living cells already present. Virchow, usually an 

 enemy to formula', coined for this I'clationship the expression onui'is 

 celluJa (h ('clluhi. 



By mmierous tests of the constitution and behavior of diseased tis- 

 sues he showed that the action of disease consists in the alteration of 

 cells, and that the life of the individual depends upon the lif(^ of his 

 cells. Nourishment, specitic functions (work), and growth are all reg- 

 ular actions of cells, while disease is an anomalous cell iU'ti\ ity. 



Virchow, aided l>y all the medical investigations which had been 

 stinudatcd by his experimental school of thought, coutimied to l)uild 

 up his pidhology upon the foundations which his discov(u-ies in cellu- 

 lar pathology had laid, and the cellular princi})le has ])een th(> basis of 

 the greatest advances of the last decade. Indeed, it would not be too 

 nuich to say that the whole modern science of biologv is built upon 

 the law of the cell succession, and it is this which has assured to Vir- 

 chow's work its undying value beyond the l)oundaries of strictly med- 

 ical science. To Ix^ sure tlu-rc has come foi-ward occasionallv the view 



