48 (;EXERAL HISTOL oc, \ : 



tissues into inucin, a'material of soft, jelly-like consistence. It 

 is a colloid substance, like gum, albumen, etc. What is called 

 colloid degeneration differs from this only in the colloid mate- 

 rial being firmer than mucus, and being more generally con- 

 fined to cells. The colloid or mucous condition is the em- 

 bryonic state of most tissues, and in the umbilical cord and 

 vitreous humor of the eye persists after birth. 



The mucus which normally covers mucous membrane is 

 derived from epithelial cells. Certain cup or goblet-shaped 

 cells occur, which some regard as producers of mucus, and 

 others as the result of mucous metamorphosis, which causes 

 them to swell and burst. The effect of chemical irritants, or 

 chronic catarrh, is not only to dilate the vessels, but to pro- 

 duce a rapid new formation of cells, which are as rapidly de- 

 stroyed by mucous metamorphosis. 



In the mucoid degeneration of cartilage the change chiefly 

 affects the matrix, which splits into fibers, whose ends taper 

 to a point and soften to mucus. In bone the solution of lime 

 salts and liquefaction of basis substance may be simultaneous 

 or otherwise. The colloid change is most common in en- 

 arged thyroid glands, in lymphatic glands, and in many new 

 formations. Colloid or mucoid tumors, or tumors which have 

 been thus transformed, are sometimes called colloid cancers, 

 although their structure may wholly differ from cancer. Some 

 forms of ovarian multilocular cysts result from colloid degen- 

 eration of the stroma of the ovaiy, and may be termed a cystic 

 colloid cancer of the ovary. 



