THE CAUSATIOX OF DISEASE. 35 I 



would be required to make good this assertion. I must 

 content myself with asking the reader to believe that I do 

 not make it without sufficient reason. Even the slow retro- 

 gressive changes of old age can in most cases be traced to 

 imperfections in the cell-E, from failure in the organs which 

 make and conduct the blood. It is at this time that fatty 

 changes abound, and that fibrous tissue begins to replace the 

 epithelial. The cell-E is no longer capable of enabling the 

 tissues to maintain their high structural standard, wherefore 

 reversion to a lower order of tissue occurs ; under the im- 

 perfect cell-E a struggle for existence ensues, and it is no 

 wonder that the hardy connective tissues increase at the expense 

 of the delicate epithelia. 



Here let me point out an important distinction between such 

 degenerations as the above, and the malignant degeneration. 

 In all cases of senile degeneration the imperfection of cell-E 

 lies in the absence of some positive essential to life, but in 

 the carcinomata there is no such absence, since growth is 

 excessive ; therefore, although the malignant growths are 

 degenerative in the strictest sense of the word, and must in con- 

 sequence be due to some modification of E, this modification is 

 quite different from that which causes the degenerations whereof 

 I. have just spoken. In malignant degeneration the abnormal 

 E must be a plus quantity ; it must contain some irritant. The 

 essentials of organic life, such as food, oxygen, and so forth, 

 must be at hand in abundance, and over and above these essen- 

 tials there must be a something which disturbs the growth of 

 the tissue as a whole (not necessarily of individual cells, for in 

 carcinoma the epithelia may grow most luxuriantly). We saw 

 that a perfect E requires not only the presence of the essential, 

 but the absence of the hurtful ; wherefore the abnormality of 

 the E of malignant tumours lies in this second particular. 

 Our present position may be thus summed up : 

 (i) Malignant disease is due to an abnormal cell-E of the 

 affected tissue. 



(2) The abnormality consists, not in the absence of the 

 essentials to life, but in the presence of some noxious agent. 



(3) The mal-environment is not wrought through the body, 

 but consists of something not of the body. 



