In 1931, J. Erdheim (4) first showed that the cartilage in acromegaly undergoes changes of both a proliferative and degenerative nature. The examples cited in his study are the cartilages of the ribs and vertebrae. The pathological process consisted of an increase in cartilaginous cells and intercellular substance, leading to a distention of the transitional zone between bone and cartilage. Proliferation was followed by degeneration with liquefaction and formation of vacuoles which were filled with deficient cartilaginous tissue. Later, ossification took place with or without previous calcification. According to Erdheim, this process of calcification and ossification may take place in the ribs and intervertebral disks in acromegaly. Another localization of these proliferative and degenerative changes in the cartilage of acromegalics was observed by H. v. Meyenburg (5), namely, the trachea and larynx. To his knowledge, his was the first such report. Experimental evidence of the action of anterior pituitary...