80 MORBID GROWTH IN GENERAL. 



due to a deposition of tlie morbid products in a very large 

 number of minute foci. Infiltration is thus intermediate between 

 uniform intumescence on the one hand, and nodal growths on 

 the other. It need hardly be added that they pass into each 

 other by countless gradations. Should, e.g., the tubercular foci 

 be somewhat larger and more isolated than usual, the infiltration 

 becomes a collection of granulations. When we find a circum- 

 scribed and solitary deposit of tubercle, as we sometimes do in 

 i\\Q brain, we call it a tuberculous nodule. 80 too, we com- 

 monly find a zone of infiltration round such knots as increase 

 rather by peripheral apposition than by central growth. In these 

 cases we may see, even with a simple lens, the creeping extension 

 to neighbouring parts, in which continuity with the parent knot 

 is never interrupted, associated with a per saltum advance, fresh 

 nodules being developed independently at short distances from 

 the periphery of the primary centre ; these enlarge, and finally 

 coalesce with the central knot. Such a zone of nodules may 

 justly be termed a zone of infiltration. Hence the phrase which 

 continually recurs in post-mortem records — " the parts adjoining 

 the tumour were already infiltrated." The transition from infil- 

 tration to uniform intumescence is determined by the degree of 

 extension of the infiltrated parts. Should the entire organ be 

 infiltrated, it is hard to see why wc should not call it uniformly 

 swollen. 



B. When the morbid products are situated on the surface of 

 an organ they assume the form of — 



4. A DESQUAMATION (desrjuamatio). This term is restricted 

 to an abundant shedding of epithelial cells. Should it be attended 

 by a considerable secretion of fluid, we call it a catarrh ; thus 

 generalising a term primarily applied to catarrh of the mucous 

 lining of the nasal fossae, in the course of which the morbid 

 secretions flow down from the nasal cavities (Karappet). 



5. A FLAT, TABULAR SWELLING (beetartige Anschwellung). 

 This corresponds to the "uniform enlargement" of parenchyma- 

 tous organs, like which, also, it is occasionally called " hyper- 

 trophy." Here too, the distinction between true and false 

 hypertrophy recurs. It diff'ers from true hypertrophy in never 

 involving the whole of a cutaneous or mucous surface ; it may 

 extend over large tracts of it, but is always separated from the 

 healthy structure at some point or other by a distinct line of 



