THE NATURAL HISTORY OF TUMOURS 



By C MANSELL MOULLIN, M.A., M.D. Oxon., F.R.C.S. 

 Consulting Surgeon to the London Hospital; Lt.-Col. R.A.M.C.T. 



The earliest sign of a tumour is a bud growing from some 

 tissue which appears to be healthy, but which in a large pro- 

 portion of instances has been subjected to continued irritation. 



These buds are like the buds which in the less highly 

 organised forms of animal life grow into organs or limbs, or 

 even complete individuals. In a sense they are independent 

 of the parent organism. Their life is not part of its life. It is 

 true they are not capable of maintaining themselves. They 

 are indebted to the parent organism for all that they want 

 in the way of sustenance. But they thrive though the parent 

 starves, and drain it of all its strength that they may con- 

 tinue to grow. They grow out from the parent organism. 

 They live upon it, but they are not part of it, and they never 

 do anything for it. 



The buds that grow into organs or limbs owe their forma- 

 tion to the power of reproducing themselves asexually which 

 the tissues possess as their birthright. In the less highly 

 organised animals this power can be exercised at almost any 

 time of life in almost any degree . With the advance of organi sa- 

 tion its activity diminishes until at last in the most highly 

 organised only certain tissues can exercise it, and these only 

 to a limited extent. Tumour buds are due to this power, or 

 rather to so much of it as the tissues retain at the moment, 

 roused into action by some exciting cause such as local irrita- 

 tion. 



Direct Reproduction 



One of the points that distinguish living organisms from 

 inert matter is their power of absorbing and assimilating 

 foreign material, in virtue of which they are able to replace 

 the waste of living, to increase in size, and when the limits 

 of size are reached, to increase in number. This power of 



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