332 ON GROWTH AND OVERGROWTH 



the other. But have we any sound grounds for assuming that the 

 presumed cancer parasite acts by stimulating and augmenting 

 the invasive powers of the cells, or by doing the reverse, namely, 

 by lowering the vitality of the tissue about to be infiltrated ? 



Looked at thus closely, it will be seen that this conception 

 of parasite acting within parasite leads to marvellous complica- 

 tions. I may be wrong, but I think that I have noted time and 

 again that when we determine fundamental laws and funda- 

 mental phenomena they are wonderful in their simplicity, so 

 that now when I find that a conception followed up leads us 

 deeper and deeper into the mire, I shrewdly suspect that the 

 conception is wrong. So it is with the parasitic theory of malig- 

 nancy as now held by so many. It may be right, some one may 

 discover the germ or germs, but neither on theoretical grounds 

 nor on the results of practical observations can I base myself 

 with any satisfaction. Certainly Gaylord's results upon this 

 side of the Atlantic do not carry conviction, and neither he nor 

 Plimmer, so it seems to me, have proved that their bodies are 

 any other than degenerative products, the abundant presence 

 of numerous forms of which in tumours was first demonstrated 

 by Fabre-Domergue, and later and most fully by Pianese. 1 



My inclinations at present, it will thus be seen, in the absence 

 of more definite discoveries, lead me to doubt very gravely the 

 permanent presence of micro-parasites in malignant growths ; 

 nor do I think that a study of the deciduoma malignum can lead 

 to any other than a firm belief that alterations in cell properties 

 and assumption of the parasitic habit by cells, I will not say, is 

 at the bottom of malignancy for we have still to determine 

 what initiates the alteration in property but must be recognized 

 and must be taken as the basis for future advance. 



Thus, to sum up what, I think, may be legitimately deduced 

 from a study of the syncytioma malignum : 



1. There exists one form of tumour of highly malignant type 

 in which the infiltrating cells are not those of the organism itself, 

 but are derived from another organism. 



2. The infiltrative and invasive properties of these cells are 

 not a new acquirement, but are an exaltation of properties 

 normally possessed by them ; or, more exactly, under normal 



1 Such bodies, described as Blastomycetea, have, I should add, been figured 

 by Rossi-Doria as found by him in two cases of deciduoma malignum. 



