HISTIOID TUMOURS. 143 



AVe call a tumour '^ malignant," not merely because it en- 

 dangers the life of its host, but because it threatens his life in 

 one particular way, by exciting a definite constitutional malady 

 which is incompatible with the due continuance of the general 

 nutrition of the organism. The symptoms of this general 

 malady (^Cachexia) are: prostration of strength, diminution in 

 the amount of blood, watery blood, emaciation, earthy tint of 

 skin, profuse sweating, diarrhoea, ha3morrhages, &c., to which 

 the patient finally succumbs. 



All attempts to detect the cause of this general disease by 

 cliemical or microscopical investigation have hitherto proved un- 

 successful. How the malignant tumour gives rise to the cachexia 

 is still unsettled. Those who regard the tumour as primarily a 

 local disease are very naturally interested in identifying the 

 marasmus in question (which is always secondary) with the 

 constitutional tumour-dyscrasia (Geschwulstkrankheit) of the 

 humoral pathologists, and in deriving both equally from the in- 

 fecting action of the malignant growth. This view has especial 

 claims upon our favour; for one thing at least remains beyond 

 all question, viz. that a stimulus is propagated from the primary 

 grov/th which excites the development of similar deposits else- 

 where, and which gradually extends its influence over the entire 

 organism. In this extension of the formative stimulus, the so- 

 called " constitutional infection," we recognise three distinct 

 stages. 



§ 118. During the first stage its operation is confined to the 

 immediate neighbourhood of the primary tumour. It determines 

 the continued production of new foci at the periphery of the 

 central growth, with which they subsequently coalesce. Malignant 

 tumours therefore invariably extend by peripheric infiltration 

 (§ 69, 3). We are obliged to assume that the impulse to morbid 

 growth precedes the growth itself by a certain interval of time. 

 This we learn from what is known as the tendency of malignant 

 tumours to recur after extirpation. Suppose we remove the 

 entire tumour, together with its zone of peripheric infiltration, 

 with a view to arrest the mischief. The incision appeared after 

 the operation to have been wholly within the limits of the healthy 

 tissue; nowhere could we detect even a trace of pathological 

 proliferation. Nevertheless, in the majority of cases we find, 

 to our dismay, that a fresh tumour, similar in character to the 



