Unfortunately I have been unable to identify the exact spots where the stalagmite was measured by Mr. Farrer, so that the only measurement which affords any trustworthy data for estimating the rate of increase is number 14. With regard to this, the only possible ground of error is the erosion of the general surface of the solid limestone, of which the roof is composed, by carbonic acid, since the year 1845, and this is so small as to be practically inappreciable. We have, therefore, evidence that the Jockey’s Cap is growing at the rate of ·2946 of an inch per annum, and that if the present rate of growth be continued it will finally arrive at the roof in about 295 years. But even this comparatively short lapse of time will probably be diminished by the growth of a pendent stalactite above, that is now being formed in place of that which measured ten inches in 1845, and has since been accidentally destroyed. It is very possible that the Jockey Cap may be the result not of the continuous but of the intermittent drip of water containing a variable quantity of carbonate of lime, and that, therefore, the present rate of growth is not a measure of its past or future condition. Its possible age in 1845 was estimated by Prof. Phillips at 259 years, on the supposition that the grain of carbonate of lime in each pint was deposited. If, however, it grew at its present rate it may be not more than 100 years old. All the stalagmites and stalactites in the Ingleborough Cave may not date further back than the time of Edward III. if the Jockey Cap be taken as a measure of the rate of deposition. INDEX. A. Abbeville, flint implements of, 16. Aborigines (palæolithic) of India, 428, 429. Acid-worn joint, Doveholes, Derbyshire, 52. Adams, Dr. Leith, explores bone-caves of Malta, 377; finds tooth of pigmy hippopotamus in Candia, 378. Adriatic Sea, the, 388. Africa, mainland of, 379; moraines in, 387; physical geography of, in pleistocene age, 370; species of European mammalia found in, 380. African animals in the Iberian peninsula, 372; elephant, the, 372, 376. Age of cavern deposits, test of, 410. Albert Cave, the, Settle, 101. Alessi, Canon, cited, 376. Algeria, fossil mammalia in, 379. Alps, the, animals living to the North of, 359, 360; glaciers of, 403. Altai mountains, the, Irish elk in, 401; panther in, 403. America, animals in, 396-399. Amiens, flint implements in the gravels of, 16. Anatolia, the glaciers of, 383-385. Anca, Baron, on caves of northern Sicily, 376. Andalusia, prehistoric antiquities in, 209.