ILLUSTRATIONS 



PLATES. 



Page. 

 Plate I. Dimorphic leaves from adjacent internodes of five plants of Hibiscus 



cannabinus, showing very abrupt changes of form 52 



ir. Dimorphic leaves from adjacent internodes of four plants of Hibiscus 



cannabinus, showing somewhat gradual changes of form 52 



III. End of fruiting branch of Egyptian cotton with normal leaves, stip- 



ules, and involucral bracts 52 



IV. End of fruiting branch of Egyptian cotton with abnormally enlarged 



stipules and reduced leaf blades, without lateral lobes 52 



V. Hybridization of broad-leaved and "okra " varieties of cotton 52 



TEXT FIGURES. 



Fig. 1. Growing tips of stalks of Hibiscus cannabinus, showing changes from 



simple to lobed leaves 12 



2. Four leaves from successive internodes of the same stalk of Hibiscus 



cannabinus, showing slight differences among the simple leaves and 

 abrupt change to the divided form 13 



3. Leaves from adjacent internodes of Hibiscus cannabinus, showing tran- 



sition from the simple to the divided form, but with the lobes 

 indicated in the simple leaf by prominent angles 14 



4. Simple-leaved Egyptian variety of Hibiscus cannabinus 15 



5. Three-lobed leaf of narrow-lobed variety of Hibiscus cannabinus, 



grown in Louisiana 16 



6. Five-lobed leaf of narrow-lobed variety of Hibiscus cannabinus, grown 



in Louisiana 17 



7. Leaves of Upland cotton seedling from first seven nodes above the 



cotyledons, showing changes of form 18 



8. Mature leaf of "King" Upland cotton, parent of " okra-leaved " varia- 



tions 19 



9. Leaf of ' ' Park's Own, " an " okra " variety of American Upland cotton ... 20 



10. Leaf of "Ratteree's Favorite," an "okra" variety of American Upland 



cotton 21 



11. Cotton leaf without lobes, a variation of the Triumph variety 22 



12. Simple leaf of fruiting branch of Egyptian cotton, produced under 



greenhouse conditions 23 



13. Young leaf from vegetative branch of Egyptian cotton, with five lobes 



and equal stipules 24 



14. Young leaf from fruiting branch of Egyptian cotton, with three lobes 



and unequal stipules 25 



15. Leaf of fruiting branch of Egyptian cotton, with abnormally reduced 



blade and enlarged, bractlike stipule 26 



J 6. Plant of Ingenhousia triloba, showing transition from entire to deeply 



divided leaves 27 



17. Simple leaf of Culluche cotton from Tuxtla (iutierrez, Mexico 32 



18. Lateral branch of the paper mulberry (Broussonetia), with leaves une- 



qual in size (anisophylly ) and diverse in form (heterophylly) 42 



221 

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