Hereditary Diseases of Cuttle. 
85 
arc found in connexion witli tlic more vascular glands about the 
head and neck, as the sublingual underneath the jaws, or the 
parotid below the ears, and are generally known under the name 
of dyers. As they arc at first hard, knotty, and painful, it is 
diflicult, or impossible, to distinguish them from ordinary fibrous 
tumours. After a variable time, liowever, they burst, and then 
their true nature is fully evident. The abscesses formed are 
unhealthy ; they rapidly extend, and pour out matter consisting 
of morbid pus and cancer-cells, which burrow into the surrounding 
tissues, and find vent by various indurating but ulcerating orifices. 
All distinct separation between tlie diseased and the healthy 
tissues is lost. The tumour appears deeply and firmly rooted by 
its broad base, is incorporated with the tissues, is vascular and 
painful, and internally dense, hard, and resisting. It is also ac- 
companied bv swelling of the absorbent vessels of the part, and 
general prostration of the system. 
Amongst the lower animals, medullary cancer is less common 
than schirrous. As its name indicates, it is soft, white, and 
pulpy, and resembles the tissues of the brain, both in appearance 
and consistence. It contains a much smaller proportion of fibrous 
matter than the schirrous variety, and a greater proportion of 
large-sized cancer-cells. Some medullary tumours are very vas- 
cular, and the vessels approach close to the surface, so that the 
slightest touch causes bleeding. When in this state, they are 
termed fungus hcematodes, or bleeding cancer. JVIedullary cancer 
is not so common in the neck, as about the eyes, or in the uterus 
and vagina. It is this variety of cancer which, in a somewhat 
modified form, occasionally affects the penis of the horse. 
Osteo-sarcomatous tumours are also hereditary. They usually 
attack the maxillary or cheek-bones, consist in the growth of a 
fungous or degenerate fleshy material, mixed with bony and calca- 
reous matter, and are attended by a very copious, unhealthy, foetid 
discharge, which usually makes its way to the surface by several 
different orifices. The bones are often so destroyed by the dis- 
ease that the teeth drop out. The progress of the disease is very 
various, but often leads to a rapidly fatal termination. These 
cancerous tumours, as well as the osteo-sarcomatous ones, must 
not, like non-malignant tumours, be considered as local maladies. 
They are but the symptoms of a diseased condition of the whole 
system, and occur only in a vitiated state of the body. Inflamma- 
tion, in such cases, is attended by effusion, not of healthy lymph, 
but of materials which cannot be assimilated with the healthy 
tissues, but are in part taken up again by the absorbent vessels, 
and thus diffused more or less generally over all parts of the 
body, destroying the integrity of the whole system. These 
materials are arrested in their progress in various of the glands, 
