90 HERBERT FE. DURHAM. 
there is an actual transference of irritating insoluble material 
to the exterior. 
In connection with this we might cite the bursting of a sub- 
cutaneous abscess (e.g. caused by and containing pathogenic 
schizomycetes) as an indirect attainment of the same result by 
means of leucocytic cells. With regard to the encapsulation 
of foreign particles, such as is above described in Dytiscus, we 
have many parallels in other animals, both with organic and 
with inorganic noxe. 
Reference has already been made to the fibrous hyperplasia 
which is caused in lymphatic glands by the irritative presence 
of pigment particles, and which prevent these particles from 
being distributed about the system. 
Are not the thick fibrous walls of chronic abscesses to be 
regarded in the same light? as also in the case of gummata 
and the well-known healed phthisical foci, in which latter the 
tough fibrous surrounding may be often seen to have entirely 
prevented a general infection of the system as well as local 
spreading of the disease. 
It seems not unlikely that in the case of carcinomata a 
similar endeavour is made by the tissues, or more exactly by 
the connective tissues, to prevent the spread of those most 
baneful growths. In those individuals whose tissues have the 
power of reacting with vigour to the stimulus, and of forming 
firm fibrous tissue readily, it is the hard scirrhus type that 
occurs ; indeed, by means of the contracting power of the new- 
formed (reactive) tissue, in rare cases the nutritive supply of 
the tumour may be so diminished that the tumour, as it were, 
cures itself (Bryant, ‘Diseases of the Breast,’ 1887, p. 142), 
or at any rate allows the patient to survive for considerable 
periods. 
On the other hand, in the softer varieties or in secondary 
growths in the liver there is little or no check upon the growth 
of the tumour, which consequently can and does spread 
rapidly. 
Such a view—viz. that the fibrous tissue present in a car- 
cinoma is formed owing to the irritation and stimulation by 
