At the suggestion of Dr. Councilman, we have undertaken in the last few years the study of the aortic and mitral valves from hearts of different ages, representing both normal and pathologic conditions. The study was undertaken in the first place to obtain more definite ideas of the normal structure of the valves, particularly the amount and relation of different tissues entering into their composition; further, to determine the period at which degenerative lesions first appear in the valves and the relation of these degenerations to the different tissues; and finally, to study the relation between such degenerative changes and acute infections.
The work will be considered under these heads:
1. Normal structure of valves and normal variations of structure with age.
2. Degenerative lesions.
3. Acute infections in relation to degenerative lesions.
The specimens were obtained from autopsies on 42 hospital patients, varying in age