12 THE SCOPE OF THE NEW METHOD 



can, by investigating the chemical cause of prolifera- 

 tion, throw considerable light on the cause of cancer. 

 Cancer is essentially a growth caused by excessive 

 cell-proliferation, and the new methods are the only 

 ones which have given us the power to induce an 

 individual cell to reproduce itself. 



As will be seen later, we can say more than this, 

 for we can induce by certain specific chemical agents 

 those remarkable asymmetrical mitotic divisions in 

 human cells which are characteristic of many of the 

 divisions which occur during malignant proliferation. 

 The latter part of this book will therefore relate to 

 Cancer Research. 



Before closing this chapter, two other points must 

 be mentioned. The usual cytological phraseology has 

 been found to be difficult to apply to many of the facts 

 seen by the new methods. For instance, the word 

 "nucleus" has a very vague meaning, and yet every one 

 uses it. It arose, we believe, from the examination of 

 cells with the lower powers of the microscope, which 

 are commonly employed in the study of "pathological 

 specimens." The nucleus of a cell, studied from this 

 aspect, is merely a deeply stained body within the cell; 

 but in reality the nucleus is composed of several dif- 

 ferent parts, each of which has a separate function 

 during cell-division. The body which appears as the 

 nucleus in some cells has a very different function to 

 that which appears as the nucleus in others. For 

 instance, the body which appears as the nucleus of a 

 lymphocyte under low magnification forms the spindle; 

 whereas what are usually described as the nuclei of_ 



