140 Trans. Acad. Sci. of St. Louis. 



EXPLANATION OF PLATES. 



1. Asimina triloba. Swelling lateral bud. 2. Terminal bud further ad- 

 vanced. 3. Cross section of bud with the two outer leaves removed. 

 4. Memspermum Cnnadense. Three superposed buds, the upper having 

 developed into a branch. 5. Three buds, side view, the two upper 

 haviDg developed. 6. Swelling bud. 7. Young branch. 8. One of 

 the first leaves. 9. Leaf-scar and bud before swelling. 

 10. Tilia Americana. Swelling bud. 11. Bud further advanced. 

 12. Xanthoxylum Americanum. Lateral bud developing. 13. Terminal bud 

 further advanced. 



14. Celastrus sca?idens. Lateral bud developing. 



15. Euonymus atropurpureus. Two young lateral branches. 



16. Ceanothus Americanus. An outer scale. 17. An inner scale. 18. A 



young leaf. 

 19. Vitis riparia. Swelling bud. 20. Young branch with bud below. 



21. Cissus Ampelopsis. Young branch. 



22. Ampelopsis quinquefolia. Swelling bud. 23. Young branch with bud 



below. 



24. Aesculus arguta. Developing terminal bud. 



25. Acer dasycarpum. Developing terminal bud. 



26. Negundo aceroides. Developing terminal bud. 27-30. Scales showing 



transition to, 31. First leaf. 



32. Staphylea trifolia. Two lateral buds developing. 33. Bud further de- 

 veloped, inner pair of scales removed ; side view, showing two young 

 leaves with their stipules. 34. Same, showing back of leaf. 



35-36. Bhus Toxicodendron. Buds in different stages of development. 



37. BMis Canadensis. Swelling bud. 38. Developing bud. 39. Young leaf. 



40. Amorpka fruticosa. Developing bud. 



41. Cercis Canadensis. Developing bud. 42. Young branch. 



43. Gymnocladus Canadensis. Swelling bud. 44. Bud further developed. 



45. Young leaf. 

 46. Gleditschia triacanthos. Base of petiole of young leaf showing minute 



stipule. 47. Developing bud, leaves cut off above the base. 48. 



Young leaf. 

 49. Prunus Chicasa. Developing bud. 50-52. Young leaves. 53. Glandu- 

 lar serration X 125 - 

 54. Prunus Americana. Developing bud. 55. Scale. 56. Inner scale or 



young leaf. 57. Stipule of developed leaf. 58. Serration of leafX 



125. 

 59. Bubus occidentalis. Young leaf. 60. Developing bud. 61-63. Scales. 

 64. Bubus villosus. Developing bud. 65. Young leaf. 66-68. Scales and 



outer leaf. 

 69. Bosa ArTcansana. Developing bud. 70. Young leaf. 

 71. Crataegus coccinea. Young branch, some of the scales at base having 



fallen off. 72-73. Two forms of stipules on young leaves. 

 74. Bibes gracile. Developing bud. 



