THE CLASSIFICATION OF TUMOURS 339 



which remains to be noted. I refer to those conditions in which 

 not individual unipotential cells of a tissue but the whole tissue 

 undergoes a local overgrowth, resulting in the formation of 

 tumours that are (1) ill-defined, (2) tend to be diffuse or multiple, 

 and (3) to retain in their structure the ordinary tissue relation- 

 ships. These are the conditions of idiopathic " Riesenwuchs " 

 of some authorities. They are commoner and more varied than, 

 I think, is usually imagined. Examples of such conditions are : 

 fibromatosis (multiple fibroids), lipomatosis, chondromatosis 

 (multiple ecchondroses) and osteomatosis (multiple exostoses), 

 myelomatosis (myeloma multiplex), gliomatosis, lymphoma- 

 tosis (including lymphatic and myelogenous leukaemia), etc. 

 Whether the termination " omatosis " should be applied to these 

 conditions is debatable. It is that which, apart from this 

 recognition of the distinction here drawn between these con- 

 ditions and the blastomas proper, has hitherto been employed 

 to designate the members of this class, and this so generally 

 that to introduce another terminology seems a work of superero- 

 gation. Such growths form a link between the tumours proper 

 and the hypertrophies. 



