DEGENERATIVE CHANGES IN TISSUE. 73 
What is fatty infiltration ? 
It is a condition similar to fatty degeneration, and in many cases it 
is impossible to make a definite distinction between the two. In fatty 
infiltration, however, it is believed that the fat originates between the 
cells, and, accumulating there, causes a passive atrophy of the cell- 
protoplasm by pressure. 
Describe amyloid degeneration. 
This is a process (sometimes termed waxy or lardaceous degenera- 
tion) in which the basement substance of various forms of connective 
tissue, and especially of the walls of bloodvessels, becomes swollen and 
thickened by its conversion into a translucent, firm, glassy, colorless 
material, albuminous in character. This material on treatment with 
iodine changes to a mahogany color. It is not known whether the 
change is brought about bya transformation of the tissue, or whether it 
is an infiltration of the tissue by some abnormal material formed else- 
where and brought to it, or is derived from the blood. 
What are corpora amylacea ? 
They are small, spheroidal, homogeneous, or lamellated bodies, which 
become of a bluish color when treated with iodine and sulphuric acid. 
They seem to have nothing to do with waxy degeneration, although 
they somewhat resemble its products. 
Describe mucoid degeneration. 
It may occur in cells or in intercellular substance. When occuring 
in cells the cell-protoplasm is transformed into a translucent semifluid 
material containing mucin. This material occupies more space than 
the cell-protoplasm, hence the cells are swollen. 
What is colloid degeneration ? 7 
It closely resembles mucoid degeneration, chemically and morpho- 
logically. Often there is no definite microscopical distinction to be 
made between the two changes. Colloid material is firmer and more 
consistent than mucoid, and contains no mucin that can be precipitated 
by acetic acid. 
What is hyaline degeneration ? 
Jt is the transformation of tissues into a transparent, glassy sub- 
stance, resembling amyloid degeneration, but it does not give the 
micro-chemical reactions of that material. 
What is the change in calcareous degeneration ? 
There is a deposition of larger and smaller granules of phosphate 
and carbonate of calcium in the intercellular substance of tissues. 
