^{page 204 note *} Camb. Phil. Trans., vol. iv., 1833Google Scholar.

^{page 204 note †} Bastardbefruchtung, 1865.

^{page 204 note ‡} Monographia Pulmonar., 1878.

^{page 204 note §} Sitz. der Kaiser. Akad. der Wissen., vol. xcvi., 1888Google Scholar.

^{page 204 note ∥} Comptes Rendus, tome cxi. No. 6, 1890; Revue Générale de Botanique, tome i. Nos. 19, 22, 23.

^{page 204 note ¶} Akad. de Wissenschaften, Munich, 1883Google Scholar.

^{page 204 note *8} Trans. Bot. Soc. Edin., vol. xix., 1891Google Scholar.

^{page 205 note *} The contributions that have recently been made (Bot. Central., Bd., xlv. xlvi.) by Schumann are exactly on the lines desiderated, and form a valuable study in tissue variability.

^{page 207 note *} Trans. Bot. Soc. Edin., vol. xix., 1891Google Scholar.

^{page 207 note †} Gard. Chron., p. 358, 1872.

^{page 208 note *} Kunth, , Enum. Plant., v. 283Google Scholar; Adans., i. 44; Bot. Mag., vol. lxxv. tome 4447; vol. lxxxii. tome 4892; Ball, Jour. Linn. Soc., vol. xxii. pp. 162–166.

^{page 208 note †} Bot. Mag., vol. lxxxii. tome 4892.

^{page 208 note ‡} Darwin, Voyage of the Beagle; Kunth, , Enum. Plant., v. 284Google Scholar; Hooker, , Flora Antartica, vol. ii. p. 355Google Scholar; Bot. Mag., vol. lxxix. tome 4738.

^{page 209 note *} In all succeeding descriptions the names of parents and hybrids are printed at the top of each page, and numbered in italics. The seed parent, if determined, is in all cases 1, the hybrid 2, and pollen parent 3. For brevity these numbers are used in the text.

^{page 212 note *} In compound or branching bundles several of these, usually of smaller size, may represent the above, and the same is true regarding the others treated of.

^{page 213 note *} For preparations of the epidermis and other parts, as also for similar preparations of other species, the potash method of maceration has proved invaluable (Proc. Brit Assoc., Aberdeen, 1885Google Scholar), since it enables one to get clean and large areas for examination.

^{page 214 note *} Comp. Anat. Phan. and Ferns, Eng. ed., 1884, p. 45.

^{page 215 note *} Pflanzen-mischlinge, p. 475.

^{page 219 note *} Jour. Linn. Soc., vol. xxi. p. 207.

^{page 225 note *} Mem. Acad. Stanisl., 1865, p. 347.

^{page 225 note †} Throughout the description I have assumed Geum rivale to be the seed parent, and G. urbanum the pollen parent. To select two plants, however, to protect these, and to raise offspring from reverse crosses for comparison, is most desirable, and our knowledge cannot be exact till this is done.

^{page 225 note ‡} The growth formation of these requires further study.

^{page 229 note *} Gardeners' Chronicle, vol. xix., n.s. 1883, p. 635Google Scholar.

^{page 237 note *} Hooker and Arnott's British Flora, 6th edit.

^{page 238 note *} It is possible that an explanation of this is got in lines of variability which 1 sometimes shows. I have pointed out (Trans. Bot. Soc. Edin., 1891) that varieties of the species may be nearly glabrous.

^{page 243 note *} “The genus Masdevallia.”

^{page 251 note *} Comp. Anat. Phan. and Ferns, Eng. ed., 1884, pp. 96–97.

^{page 252 note *} I am greatly indebted to Mr Grieve of Messrs Dickson's nurseries for a liberal supply of this hybrid that was raised by him.

^{page 253 note *} Gardeners' Chronicle, vol. ix. p. 618, 1891Google Scholar; Trans. Roy. Hort. Soc., 1891.

^{page 254 note *} Darwin, , Animals and Plants, vol. i. p. 414Google Scholar.

^{page 256 note *} Trans. Bot. Soc. Edin., vol. xvii., 1888Google Scholar.

^{page 259 note *} Animals and Plants under Domestication, 2nd edit., 1890, vol. . pp. 413–417.Google Scholar

^{page 259 note †} Annales de la Soc. de l'Hort. de Paris, tom, vii., 1830, p. 93; Loudon's, Gard. Mag., vol. vi., 1831, p. 335Google Scholar; viii., 1832, pp. 473–474; The Phytologist, vol. i. pp. 652, 908; Gard. Ghron., 1841, pp. 265, 325, 336; 1842, p. 397; 1857, pp. 382, 400, 454; 1864, p. 244; 1865, p. 509; 1866, pp. 565, 733; 1868, p. 575; 1870, pp. 767, 831; 1884, pp. 772, 810, 811; Braun, , “Rejuvenescence,” Ray Soc. Bot. Mem., 1853Google Scholar; Bot. Zeitung, 1873; Focke, , Pflanzen-Mischlinge, pp. 519–522Google Scholar; Darwin, , Animals and Plants under Domestication, 2nd edit., 1890, vol. i., pp. 413–417Google Scholar; Morren, E., Belgique Horticole, vol. xxi., 1871Google Scholar; Caspary, , Bullet du Congrès Internal de Botanique, Amsterdam, 1865, p. 72Google Scholar; Masters, “Grafting, its Consequences and Effects,” Popular Science Review, April, 1871; Macfarlane, , Gard. Ghron., July 26, 1890Google Scholar.

^{page 259 note ‡} Masters, Gard. chron., “Bud Variations,” 1891; Focke, Pflanzen-Mischlinge, p. 21.

^{page 259 note §} Comptes Rendus, August 1890.

^{page 270 note *} Abhand. d. Senckenb. nat. Gesell., Bd. xii.

^{page 270 note †} Animals and Plants under Domestication, 2nd edit., vol. i. pp. 419–422.

^{page 273 note *} Recherches sur la maturation de l'æuf, 1883.

^{page 274 note *} I should state here that the gland hair figured from R. nigrum (Plate V. fig. 13) is slightly larger than the average, and that from the hybrid smaller, but for microphotographic work one has sometimes to choose material that shows the objects, even though these are not of average size. The cell details also are lost in the figure.

^{page 274 note †} This is a very instructive hybrid that was gathered in Inverness-shire by Messrs Jenner and Howie, and of which abundant material has been secured for future description.

^{page 275 note *} The Law of Heredity, Baltimore, 1885Google Scholar.

^{page 275 note †} Neue Untersuchungen, p. 163.

^{page 276 note *} Neue Untersuchungen, p. 194.

^{page 278 note *} Biological Memoirs, first English ed., pp. 180, 181.

^{page 279 note *} Trans. Roy. Soc. Edin., vol. xxx., 1881–1882Google Scholar.

^{page 279 note †} Confirmatory observations on two species of Spirogyra will shortly be published, giving details.

^{page 279 note ‡} Trans. Bot. Soc. Edin., vol. xiv., 1882Google Scholar.

^{page 281 note *} “The Origin of Sex,” Proc. Amer. Phil Soc., vol. xxviii.

^{page 282 note *} The Independent, No. 1063, New York.

^{page 282 note †} Proceedings of the Cotteswold Club, 1888–89.