319 



-cancer is formed in the body is simply that some substance is pre- 

 sent in the blood which so highly sensitizes ourselves that it 

 becomes possible for our own blood to partially liquefy or fertilize 

 our own cells. 



To cause the liquefaction of a superficial area of a cell so as 

 to make those liquefied droplets fuse together seems to be the only 

 thing necessary to start the whole process of development. There 

 is an interesting side issue attached to this fact. What becomes 

 of the function of the spermatozoon? Apart from the question 

 of inheritance, which we shall leave out of consideration this 

 evening, its only function apjpears to be that of liquefying the 

 surface layer of the egg which it enters. We are led to believe 

 that the egg already contains everything necessary for its develop- 

 ment, and necessary to start the processes of cell division, growth, 

 and development, but that they cannot mix, and it is necessary 

 that they should mix first. Around the superficial layer of the 

 cell there would appear to exist a sort of solid emulsion of fat 

 which, if mixed with the material of the cell, would cause the 

 cell to develop, but it cannot mix because it is held in the super- 

 ficial layer by the solid fat within that superficial layer. Directly 

 that fat has dissolved it is free to enter the cell and develop. 

 Whether we start it with spermatozoa, or with the blood of 

 another animal, with acids or with any of the other substances 

 I have mentioned is quite immaterial. All that is necessary is to 

 mix the constituents which the egg-cell already contains. 

 Therefore it is analogous to those fire extinguishers which only 

 have to be turned upside down to produce a stream of carbonic 

 gas which puts out the fire. Two things are held within the fire 

 extinguisher, separated from one another, and until they are 

 mixed nothing happens. Mix them, and immediately a chain of 

 process occurs which, more or less, is beyond our control. Here 

 we have stored up within each of our cells unlimited potentialities 

 for cell division, growth, and development, and only the fact that 

 two things Avhich must mix are in different parts of the cell, and 

 are kept in the different parts by the physical properties of those 

 different parts, prevents those potentialities from being set 

 free. Directly the outer layer and the inner part of the cell mix, 

 the whole chain of process occurs. It would be very easy for me 

 to go on to almost any time to-night talking about things just as 

 interesting as these, and wearying you doubtless in the process, 

 but I shall have mercy on you, and cease before you request me 

 to do so. 



In conclusion, it may relieve some of my audience and readers 

 to know that all of the surgical operations to which I have alluded 

 in this lecture, and in the accompanying note, were conducted 

 under complete anaesthesia, and with all possible regard for the 

 comfort and well-being of the animals. 



SUPPLEMENTARY NOTE BY PROFESSOR ROBERTSON. 



In delivering the above lecture the lateness of the hour com- 

 pelled me, greatly to my regret, to omit the discussion of one of 

 the most interesting questions arising out of this field of investi- 

 gation. I refer to the question whether or not death is a really 

 necessary phenomenon — whether it is inevitably implied in growth, 

 ■or whether it is not something superadded upon growth — some- 



