350 



Chondroma. 



which have become oedematous from lymphstasis, simulate 

 myxomata (fibroma myxomatodes), the absence of mucin or its 

 scanty proportion in the fluid content distinguishing them from 

 the true myxoma. 



Myxomata develop as single or more or less multiple primary 

 growths according to their situation, and as sarcomatous mixed 



tumors capable of metastasis and of 

 embryonic appearance. They are es- 

 pecially met upon and in the heart 

 of cattle (when the subperi cardial 

 and subendocardial foetal mucous tis- 

 sue acts as their developmental sub- 

 stance) as rounded, lobulated growths 

 ranging in size from that of a nut to 

 tliat of a fist ; they also occur in the 

 nose in the cow and horse, in the 

 parotid, and in one case in the dog 

 around the spinal cord (Holzmann). 

 and, too, in cattle along the nerve 

 trunks (neuromyxoma). The gela- 

 tinous, glassy, swollen, yellowish 

 (sometimes like flesh of the cod- 

 fish) appearance, their softness and the ropy mucoid character of 

 their substance, constitute their important distinguishing features. 



Fig. 02. 



Myxofibroma of the heart, from 

 cow. 



Chondromata. 



A chondroma or cartilaginous tumor has, in addition to a 

 vascular fibrous connective tissue framework, as its main con- 

 stituent cartilaginous tissue, usually of the hyaline type, and 

 contains cartilaginous cells of very irregular size encapsulated in 

 this substance without regularity of arrangement. The fibrous 

 tissue forms a capsule and the trabecular framework about the dif- 

 ferent cartilaginous areas (which occur as islands and lobulated 

 nodules in the tumor) and acts as their nutritive perichondrium. 



Besides the pure chondromata there are met manv mixed 

 types, made up of fibrous tissue, bone and glandular tissue, in 

 which cartilage enters as only one of the constituents ; and modifi- 

 cations may also result from the rather marked tendencv of the 

 cartilage to metamorphosis, both regressive and progressive. Mu- 

 coid degeneration with production of gelatinous softened foci 

 (cysts), and calcification, giving rise to white opaque patches 



