BURRILL, Thomas Jonathan, naturalist, born in Pittsfield, Massachusetts,25 April, 1839. He was graduated at the Illinois state normal University in 1865, where, in 1868, he was elected professor of botany and horticulture. From 1877 till 1884 he was dean of the department of natural sciences, and in 1882 he became vice-president of the university. In connection with his botanical studies, Prof. Bur-rill has traveled extensively through the United States and Central America, and was a member of Maj. J. W. Powell's first expedition to the Rocky mountains in 1867. He has made careful studies of the diseases of plants, and, after his investigations on the "Pear-Tree Blight" during 1878-'80, announced that bacteria were a cause of disease in plants. In 1878 he was president of the Illinois state horticultural society, during 1883-'4 vice-president of the American horticultural society, vice-president of the section of biology of the American association for the advancement of science, and in 1885-'6 president of the American society of microscopists. He edited the biennial reports of the University of Illinois during the years 1874 to 1886, and has written many papers and pamphlets, among which are "The Bacteria" (Springfield, 1882) and the " Uredineae, or Parasitic Fungi of Illinois" (Peoria, 1885).