THE Annual Exhibition of the Royal Photographic Society at 35 Russell Square remains open until October 28. Admission is free. The natural history section of the scientific and technical division has improved considerably in recent years. There are still a good many single photographs of an animal, a flower, or an insect that have no particular interest, or if they have it is not indicated; but there are many series showing progressive changes, such as Dr. S. Hastings's nine illustrations of soil formation in the Alps, in which he shows the bare rock covered at first with crustaceous lichens, and traces the stages of vegetation until an alpine meadow is produced. Other series show many varieties of the same kind of thing, as Mr. C. H. Caffyn's thirty sections of calcareous, arenaceous, and igneous rocks, and Dr. Rodman's animal and vegetable hairs. With scarcely any exception the photography in this section is excellent.