Wallace Line to the west of the Philippines. Wallace's studies in Indonesia demonstrated the emerging theory of evolution, at about the same time as Joseph Dalton Hooker and Asa Gray published essays also supporting Darwin's hypothesis. Understanding of the biogeography of the region centers on the relationship of ancient sea levels to the continental shelves. Wallace's Line is visible geographically when the continental shelf contours are examined; it can be seen as a deep-water channel that marks the southeastern edge of the Sunda Shelf which links Borneo, Bali, Java, and Sumatra underwater to the mainland of southeastern Asia. Australia is likewise connected
Acephalous line Acephalous line An acephalous or headless line is a variety of catalectic line in a poem which does not conform to its accepted metre, due to the first syllable's omission. Acephalous lines are usually deliberate variations in scansion, but this is not always obvious. It is a technique employed often in the concluding lines of hymn texts, and has been employed in poetry to change tone or announce a conclusion, including its use in Joyce Kilmer's "Trees" and A. E. Housman's "To An Athlete Dying Young." Robert Wallace argues in his essay "Meter in English" that the term "acephalous line"