148 ' ROBERT TRACY JACKSOX ON 



Fig. 60. Sucker from the base of an adult tree. Leave.s 4-5 simple, ovate ; leaves 6-7 abnormal, with one lateral leaflet ; 

 leaves 9-10 trifoliolate. Xi. P. 110. 



Fig. 61. Tip of branch of an adult, shovving 1, typical lr;if "f the species; 2, trifoliolate leaf occurring typically at the 

 end of branches. Compare with Figs. 59-60. Xi. Figs. 5y-<il, Milton, Mass. P. 110. 



QUERCUS ALBA. 



Fig. 62. Seedling showing cotyledons enclosed in the acurn and succeeding nepionic leaves, 1, elongate, oval, very 

 slightly sinuate ; leaves 2-3 slightly lobed. Xl- P. 111. 



Fig. 63. Sucker from the base of an adult tree. Leaf 1 nearly entire; later leaves progres.sively more lobate. X.t 

 P. 111. 



Fig. 64. Typical leaf of adult. X^. P. 111. 



Qdercus minor. 



Fig. 65. Sucker from the base of an adult tree, leaves nearly entire, 1 oval, 2 obovate, slightly lobed. Xi. PI. 111. 

 Fig. 66. Typical leaf of adult. Xj. P.m. 



QuERCnS TINCTORIA, OR Q. COCCINEA. 



Fig. 67. Seedling, cotyledons enclosed in acorn (di.ssected out in diagram). Nepionic leaves 1-3 oval, with a small 

 spine at end of the midrib ; leaf 4, slightly undulous with spines at the tips of the principal veins. X j- P. 111. 



Fig. 68. Seedling showing the petioles of the cotyledons extending from the acorn as in other figm-es. First leaves 

 small, entire ; leaves 3-4 miicli larger, undulous, with .spines at tijjs of principal veins, x '. P. 1 1 1. 



QlERClIS TINCTORIA. 



Fig. 69. Sucker from the b:\se of an adult. First leaf oval with a .spine at the tip of the midrib, later leaves undulous, 

 or lobed. Compare with Figs. 67-68. X I- P- 112. 



Fig. 70. Suckers from the ba.se of an adult. First leaf tindtdous with spines at tips of leading veins; next leaf more 

 lobed. Compare with Fig. 68. XI P. 112. 



Fig. 71. Typical leaf of adult. X\- Figures 62-71 from West Chop, Martha's Vineyard, Mass. P. 112. 



Figs. 59-7 1 drawn by the author. 



PLATE 21. 



PiNUS RIGIDA. 



Fig. 72. Seedling showing cotyledons bound together distally by the remains of the seed coats, and nepionic leaves pro- 

 truding thickly from the .short stem. XH. P. 113. 



Fig. 73. A little older seedling showing cotyledons free distally, smooth, triangular in section (Fig. 73, b). Nepionic 

 leaves thickly clothing the stem, the individual leaves, Fig. 73a, flat on the inner side, curved on the outer side with two 

 marginal rows of serrate spines, xi. P. 113. 



Fig. 74. Older seedling showing the nepionic primary leaves at the base, succeeded by clusters of needles in the 

 axils of primary leaves. X|. P. 114. 



Fig. 74a. Cluster of needles in the axil of a primary leaf from the tip of Fig. 74. Xl. Fig. 74b. Section of cluster 

 at the base where surroiuided by a sheath. Fig. 74c. Fragment of one of cluster leaves showing form and the rows of 

 minute saw-like teeth on the three angidar ridges. Enlarged. I'. 114. 



Fig. 75. Cluster of leaves in the axil of a scale from an older seedling, which in this feature has attained adult 

 characters. X|. P- 114. 



Fig. 76. Sucker from a stump showing reversionary primary leaves with bundles in their axils as in the later growth of 



