Anna Comstock defined the idea extensively in her book, Handbook of Nature Study: "Nature Study is for the comprehension of the Individual life of the bird, insect or plant that is nearest at hand."[8] Comstock continued that nature study aided "both discernment and in expression of things as they are".[9] The movement came at a time when society was concerned with the future of the next generation[10] and with nature conservation itself,[11] and because of this was met with high regard and high expectations.[10] Though many efforts had come before 1890 by some naturalists and scientists to teach and expand the movement, the nature-study movement really did not gain momentum with the public until the late 19th century.[10] By 1925, the subject had found a place in the curriculum of almost every school district in the United States.[12]