XXVIII. The Crayfish: an Introduction to the Study of Zoology. By Professor T. H. Huxley. With 82 Illustrations. Third Edition. Crown 8vo, 5s.
XXIX. The Brain as an Organ of Mind. By H. Charlton Bastian, M.D. With numerous Illustrations, Third Edition. Crown 8vo, 5s.
XXX. The Atomic Theory. By Prof. Wurtz. Translated by G. Cleminshaw, F.C.S. Third Edition. Crown 8vo, 5s.
XXXI. The Natural Conditions of Existence as they affect Animal Life. By Karl Semper. With 2 Maps and 106 Woodcuts. Third Edition. Crown 8vo, 5s.
XXXII. General Physiology of Muscles and Nerves. By Prof. J. Rosenthal. Third Edition. With Illustrations. Crown 8vo, 5s.
XXXIII. Sight: an Exposition of the Principles of Monocular and Binocular Vision. By Joseph le Conte, LL.D. Second Edition. With 132 Illustrations. Crown 8vo, 5s.
XXXIV. Illusions: a Psychological Study. By James Sully. Second Edition. Crown 8vo, 5s.
XXXV. Volcanoes: what they are and what they teach. By Professor J. W. Judd, F.R.S. With 92 Illustrations on Wood. Second Edition. Crown 8vo, 5s.
XXXVI. Suicide: an Essay in Comparative Moral Statistics. By Prof. E. Morselli. Second Edition. With Diagrams. Crown 8vo, 5s.
XXXVII. The Brain and its Functions. By J. Luys. With Illustrations. Second Edition. Crown 8vo, 5s.