LIST OF ILLUSTRATIONS 



Fig. Page 



1. 



A. The Oak-leaved Hazelnut (Corylus Avellana laciniata), 

 a natural sport of the ordinary hazelnut (B) ... 7 



2. A. The toadflax (Liimria vulgaris). B, C. Its peloric va- 



riety. D. A peloric flower on an ordinary specimen . 12 



3. A. The Double-flowered Corn-marigold {Chrysanthemum 



segctum plenum), an experimental mutation produced at 

 Amsterdam, 1899. B. A flower-head of the original cul- 

 tivated variety. C. The first result of selection. D. The 

 first sign of doubling. E. A typical double flower-head , 13 



4. The Experiment Garden in the botanical garden at Am- 



sterdam, covered with iron wire netting. Cultures of 

 different Evening Primroses, some enclosed in bags for 

 artificial pollination, 1904 ...... 15 



5. Lamarck's Evening Primrose {Oenothera Lamar ckiana), a 



mutating species . . . . . 17 



6. Leaves of Lamarck's Evening Primrose (A), and of two of 



its mutants (B. Oen. lata. C. Oen. scintillans) . . 19 



7. Mutants of the Evening Primrose. A. The red-veined 



form (O. rubrinervis) which is of the same size as the 

 original species. B. and C. The dwarfish variety {Oen. 

 nanella) ......... 21 



8. A flower-spike of the giant-mutant {Oenothera gigas), which 



originated in my garden, 1896 ..... 23 



9. A flower-spike of the red-veined mutant {Oenothera rub- 



rinervis), which has been produced almost yearly by the 

 parent species ........ 25 



10. Dr. Hjalmar Nilsson, Director ot the Swedish Agricultural 



Experiment Station at Svalof ..... 28 



11. Poland wheat (Triticiim polonicum) .... 30 



12. A. Belle vue de Talavera-wheat, isolated by Le Couteur. 



B. Bearded white wheat, produced by Patrick Shirreff. 



C. Squarehead wheat, the most famous production of 



th^ same breeder ....... 32 



13. A. Hallett's pedigree Chevalier barley. B. Hallett's pedi- 



gree wheat ........ 39 



14. A reproduction of part of the first advertisement of pedi- 



gree wheat by F. F. Hallett. See the Times, London, 

 June 18, Nov. 8 and Dec. 19, 1862 .... 40 



15. The Swedish Agricultural Experiment Station at Svalof. 



Part of the campus and residence of the Director . . 49 



16. The new building of the Swedish Experiment Station at 



Svalof, erected 1907. ...... 53 



vii 



