r):
on "Descent of Man," ii. 31-2;
on physiology of ferns, etc., 40-1;
on infinity of life-forms, 89-90;
on house-planning at Broadstone, 119-20;
on Turks, 153;
on his "Reciprocity" article, 153;
on the earth as only habitable planet, 175;
on Spiritualism, 188-95;
on psychical and other works, 203-4;
on his visit to Switzerland, 204;
on re-incarnation and theosophical writings, 205;
on psychical research and Spencer's "Autobiography," 211;
on conferment of Order of Merit, 222;
on his autobiography, and Owen, 224-5;
on reviews of "My Life," 225-6

---- ---- ---- letter to Mr. Sydney C. Cockerell, on Kropotkin's Life,
ii. 161

---- ---- ---- letter to Mr. Theo. D.A. Cockerell, on fertilisation,
ii. 49

---- ---- ---- letters to Charles Darwin:
on the Timor honeycomb, i. 143;
on Darwin's "Orchids," 143;
on theory of flight, 145;
on Spencer's "Social Statics," 150;
on Borneo exploration and his contribution to theory of man's origin,
152;
on his paper on Man and Natural Selection, 155;
on the Aru Islands, 161;
on a case of variation becoming hereditary, 162;
on the _Reader_, 165;
on dimorphism, 168;
suggesting "survival of the fittest" in preference to "natural
selection," 170;
on mimicry and glacier action, 176;
on expression, 180;
on "Creation by Law," 188, 192;
on superintendency of a Museum, 193;
on sterility of hybrids, 196;
on natural selection as producing sterility of hybrids, and pangenesis,
199;
on Trimen's paper at the Linnean Society, 201;
on selective sterility, 203, 205, 210;
on Darwin's "Cross Unions of Dimorphic Plants," 218;
on protection and sexual selection, 221, 222, 227;
on the dedication of "Malayan Travels," etc., 232;
on single variations, 234;
on colouring of caterpillars, 235;
on his "unscientific" opinions on Man, 243, 250, 255;
on wing-scales of butterflies, 244;
on Dr. Meyer, 248;
on "Descent of Man," 255, 259, 284;
recommending two remarkable books, 263;
on Mivart and Chauncey Wright's critique, 265;
on Darwin's answer to Mivart, 271;
on Dr. Bree, and Bastian's "Beginnings of Life," 273;
on a Bethnal Green Museum appointment, 277;
on Darwin's "Expression of the Emotions," 279;
on invitation to undertake revision work for Darwin, 281, 282;
on "Climbing Plants," 285;
on Darwin's criticism of "Geographical Distribution," 288, 294;
on Darwin's "Cr