Josué, M., artificial production of atheroma, 32 Jousset, Dr., on difference between man and apes, 184 Kant, 309, 310 Kautsky, on socialism, 229, 230 Kentigern, age of, 87 Kephir, 171, 172, 173 Khoury, M., on ferment of Egyptian milk, 105 Kocher, Dr., on effects of extirpation of thyroid gland, 33 Kocher, Prof., case of removal of large intestine, 152, 153 Kölliker, on degeneration of muscles, 27 Koppenfels, on character of gorilla, 194 Koumiss, 172 Kowalevsky, Sophie, 225 Kowalevsky, analysis of pessimism, 241, 255 Kukula, experiments on intestinal poisons, 69, 70 Kwass, 166 Lactic bacilli, and putrefaction in intestine, 168 Laignel-Lavastine, M., criticism of neuronophagy, 20 Lankester, Sir E. Ray, on longevity, 12, 56 Lao-Tsé, and immortality, 137 Laud, Archbishop, old tortoise of, 51 Lautschenberger, on absorption in colon, 64 Lavater, Goethe’s letter to, 268 Laws aiding the aged, 3, 4 “Leben,” Egyptian, 105, 171, 177, 178 Le Bon, G., on hysteria in crowds, 209 Lenau, M., 236 Lenthéric, on elephants swimming, 197 Leopardi, G., pessimistic poet, 235, 236, 247 Le Play, M., on putrefactive poisons, 69 Léri, M., on senile brain, 20 Lermontoff, 236 Leucomaines, as cause of sleep, 121 Levaillant, on longevity of parrots, 52 Lewes, G. H., on Goethe, 273, 290, 292, 298 Lexis, on duration of human life, 85 Life, duration of, in animals, 39 _et seq._ Life, prolongation of human, 132, _et seq._ “sense” of, 260 Lima, Dr., on use of soured milk in Africa, 172, 174 Lloyd, M., old anemone of, 47 Loewenberg, Dr., on Mde. Robineau, 7 London Zoological Gardens, 51, 81 Longevity, in animal kingdom, 47 _et seq._ human, 84 _et seq._ rules for, 141 in sexes, 44 theories of, 39 Lorand, Dr., on ductless glands, 32 Love, Goethe and, 272 Luxury, 321 Macfadyen, Nencki and Mde. Sieber, on digestion, 153, 161 Macrophags, 25, 147 Mailaender, 235, 255 Malaquin, M., on _Monstrilla_, 116, 117 Male rotifers, death of, 114, 115 Malthus, theory of, 214 Mammals, longevity of, 53 Mammary glands, in males, 186 Man, compared with apes, 184, 185 natural death of, 119 _et seq._ longevity of, 84 _et seq._ Manouélian, M., on neuronophagy, 21, 22 Marinesco, M., on neuronophogs, 19 Marrow of the bones, in old age, 37 _Marsiliaceæ_, duration of life of prothallus, 99 Martin, on Gibbons, 192 Massart, on cause of death in plants, 102, 109 Massol, Prof., 178 Mastication, and intestinal putrefaction, 160 Matchinsky, M., on atrophy of ovary, 26 Maternal instinct, 319, 320 Mauclaire, M., operations on large intestine, 153, 154, 155 Maumus, M., on digestion in cæca, 61 Mauritius, giant tortoise from, 12 Maupas, M., on infusoria, 13 Maya, 178 Mayers, on Chinese elixir, 138 Meconium, appearance of microbes in, 161 Medical selection, 134