LIST OF ILLUSTRATIONS 



PAGE 

 Fig. 1. Polarity in regeneration of cut tubers of Corydalis 



solida 6 



Fig. 2. Eetention of specific characteristics by grafts of 



fruits of three varieties of gourds 13 



Fig. 3. Eetention of specific characteristics by grafts be- 

 tween two species of tadpoles 14 



Fig. 4. Production of lens by grafted belly epithelium of a 



toad, under induction from the eye-cup of a frog 15 



Fig. 5. Gottlieb Haberlandt 16 



Fig. 6. Ross G. Harrison 23 



Fig. 7. Warren H. Lewis 24 



Fig. 8. Margaret R. (Mrs. Warren H.) Lewis 25 



Fig. 9. Alexis Carrel 26 



Fig. 10. W. Kotte 37 



Fig. 11. R. J. Gautheret 38 



Fig. 12. Philip R. White 39 



Fig. 13. Roots of tomato, white clover, and red clover 40 



Fig. 14. Section of seed of Peperomia hispidula 46 



Fig. 15. Undifferentiated embryo of Peperomia hispidula 47 



Fig. 16. Leaves regenerated on root of dandelion 51 



Fig. 17. Cultures of sunflower tissues 52 



Fig. 18. Cultures of Nicotiana callus 53 



Fig. 19. Cultures of bacteria-free crown-gall tissues of sun- 

 flower 53 



Fig. 20. Young embryo of Portulaca oleracea 54 



Fig. 21. Root cap on root of white clover 61 



Fig. 22. Root-hairs on growing excised tomato root 62 



Fig. 23. Root-hairs on growing excised buckwheat root 63 



Fig. 24. Growing excised roots of tomato and buckwheat 64 



Fig. 25. Plan of a laboratory suite 68 



Fig. 26. Week by week increment rates of excised roots over 



eight years 78 



xi 



