Before proceeding to a discussion of the treatment of pterygium it would be well to consider the nature of the growth and the circumstances under which it develops. So eminent an authority as Prof. Fuchs speaks of pterygium as a growth peculiar to those past middle life, and while this may be true of Vienna and the country surrounding that city, it certainly is not true of the southwestern part of the United States, where I have been practicing ophthalmology for a number of years. In this region, where we have the combination of summer heat from April to November, with a dry atmosphere agitated by high winds and impregnated with alkaline dust, we will find the ideal conditions for the development of pterygia. Consequently, it is not at all infrequent to see boys in that country afflicted with pterygia of small size, while among those who are older we