Trans. Roy. Soc. Edin. 37: 203-286 (1892)
XIV.—A Comparison of the Minute Structure of Plant Hybrids with that of their  Parents,
and its Bearing on Biological Problems.

By J. MUIRHEAD MACFARLANE, D.Sc., F.R.S.E. (Plates I.-VIII.)

(Read 4th May and 15th June 1891.)


    PAGE
I. INTRODUCTION 203
II. COMPARISON OF HYBRID STRUCTURE WITH THAT OF THE PARENTS—  
  (a) Philageria Veitchii 207
  (b) Dianthus Grievei 220
  (c) Geum intermedium 225
  (d) Ribes Culverwellii 229
  (e) Saxifraga Andrewsii 232
  (f) Erica Watsoni 237
  (g) Bryanthus erectus 238
  (h) Masdevallia Chelsoni 242
  (i) Cypripedium Leeanum 245
  (k) General Observations 249
III. COMPARISON OF THE COLOUR, CHEMICAL CONSTITUTION, ODOUR, FLOWERING PERIOD, AND CONSTITUTIONAL VIGOUR OF HYBRIDS, WITH THOSE OF THE PARENTS, 254
IV. HISTORY AND STRUCTURE OF Cytisus Adami 259
V. GENERAL SUMMARY OF RESULTS ON SEED HYBRIDS, 270
VI. THE BEARING OF HYBRIDITY ON BIOLOGICAL PROBLEMS—  
  (a) Relative Potency of the Male and Female Sex Elements in the Formation of an Organism, 272
  (b) Unisexual Heredity, 273
  (c) Bisexual Heredity, 274
  (d) On the Divergence of some Hybrids, or Parts of Hybrids, towards one Parent 275
  (e) Mechanical or Physiological Obstacles to Fertilisation as an Explanation of Infertility in some Hybrids, 276
  (f) The Relative Fertility of Hybrids in Relation to Heredity, 277
  (g) Vegetable Cell Structure in Relation to Hybridity, 278
  (h) Value of Microscopic Characters in the Future Verification of Doubtful Hybrids, 281
  (i) A Consideration of the Possible Origin of Species from Hybrids, 282

Plate I Plate II Plate III Plate IV Plate V Plate VI Plate VII Plate VIII