AN address on progress in biology during the last of hundred years has one element of simplicity; since, with scarcely a tinge of exaggeration, the whole subject from its inception may be held included. Though the materials studied by biologists are those which have been the objects of man's curiosity from the earliest times, yet the biological way of looking at them was new, and biology was a term deliberately selected to proclaim the consciousness of a new hope. Tre-viranus-Gottfried Reinhold, 1776-1837, of Bremen, elder brother of the well-known botanist Ludolf Christian (1779-1864)-was the first to use the word Biology (1802). He complained that the current treatments both of zoology and botany were lacking in penetration and in comprehensiveness, and that their practitioners were too often giving a divided attention, with an eye ever wandering towards medicine and other applications. The catalogues of plants and animals, and barren descriptions compiled in the name of those sciences, are a beginning, not an end. They are the materials which the science of living things is to absorb and co-ordinate. The problem before the biologist is, What is Life? and the collections have value in so far as they contribute to a solution of that problem.