VI TREE ANCESTORS 



Fig. 24. Some fossil birches 115 



Fig. 25. Some fossil hazels 117 



Fig. 26. Some fossil beeches 125 



Fig. 27. Map of the world showing the present distribution of the oaks. . 132 

 Fig. 28. Map of the world showing the distribution of the beeches and of 



Castanopsis 135 



Fig. 29. Map of the world showing the modern distribution and the fossil 



occurrences of the chestnut 141 



Fig. 30. IMap of the world showing the modern distribution of Pasania and 



the ancestral genus Dryophyllum 142 



Fig. 31. Some existing and extinct oak leaves 145 



Fig. 32. Some existing and fossil elms and hackberries 151 



Fig. 33. Ancestral forms of buttonball leaves 161 



Fig. 34. IMap of the world showing the fossil occurrences of magnolias. . . 166 

 Fig. 35. Map of the world showing the distribution of the genera of the 



magnolia family 166 



Fig. 36. Map of the world showing the existing distribution and fossil 



occurrences of the tulip-tree 172 



Fig. 37. Some singular atavistic leaves of the tulip-tree 175 



Fig. 38. Some fossil leaves of the ancestral tulip-trees 177 



Fig. 39. ]\Iap of the world showing the present distribution and the fossil 



occurrences of the sweet gum 183 



Fig. 40. Some fossil leaves and fruits of the sweet gum 187 



Fig. 41. Some fossil red buds 192 



Fig. 42. Some fossil locusts and coffee beans 195 



Fig. 43. Some fossil maple leaves and fruits 219 



Fig. 44. Map of the world showing the present distribution and the fossil 



occurrences of the tupelo 245 



Fig. 45. ]\lap of the world showing the present distribution and the fossil 



occurrences of the sassafras 248 



Fig. 46. Some Pliocene sassafras leaves from Europe 250 



Fig. 47. Map of the world showing the existing and geological distribution 



of the persimmons 259 



Fig. 48. Some leaves and fruits of fossil species of persimmon 261 



