TUMOURS. 



419 



Suh-section 1. — Malignant Tumours, 



The former essentially depend upon constitutional con- 

 ditions and exhibit a tendency to infective distribution. 

 They are specific in their character, and are commonly 



known as Cancers or Carcinomata. We have had 

 occasion already to notice the cachexia which results 

 from constitutional impregnation with cancerous matter, 

 and have shown how cancer may be generated by a 

 process of grafting, so that local developments may be 

 either the cause or result of constitutional conditions. 

 This local manifestation either assumes the character of 

 an infiltration or more frequently of a tumour. The latter 

 is less dangerous to the system than the former; its 

 virulent cells are confined and are less liable to invade 

 important organs ; also the case may be palliated by 

 removal of the masses of specific cells. The cachexia 

 remains in a scarcely manifest state throughout the stage 

 of generation of the tumours, and according as the latter 

 have a soft or a hard character is the rapidity of systemic 

 complication ; when the swelling begins to soften the. 

 infective processes are in their greatest activity. Carcino- 

 mata are of several kinds : 





Fig. 83. — Scirrhous growth from mammary gland, x 200, (After Harley 



and Brown.) 



SciREHus, dense, hard, generally lobulated, consisting 



