Wallace Line genus of plants which does not cross the Line is the Australasian genus "Eucalyptus". Antonio Pigafetta had recorded the biological contrasts between the Philippines and the Maluku Islands (Spice Islands) (on opposite sides of the line) in 1521 during the continuation of the voyage of Ferdinand Magellan, after Magellan had been killed on Mactan. Moreover, as noted by Wallace himself, the observations in faunal differences between the two regions had already been made earlier by English navigator George Windsor Earl. In Earl's pamphlet "On the Physical Geography of South-Eastern Asia and Australia", published in 1845, he described how shallow seas
Sundaland Russel Wallace as the eastern boundary of the range of Asia's land mammal fauna, and thus the boundary of the Indomalaya and Australasia ecozones. The islands east of the Wallace line are known as Wallacea, a separate biogeographical region that is considered part of Australasia. The Wallace Line corresponds to a deep-water channel that has never been crossed by any land bridges. The northern border of Sundaland is more difficult to define in bathymetric terms; a phytogeographic transition at approximately 9ºN is considered to be the northern boundary. Greater portions of Sundaland were most recently exposed during the last glacial