LOCALIZED STAGES IN DEVELOPMENT. HI 



fig. 60) shows interesting features. The first three leaves are wanting, the fourth and 

 fifth are simple, resembling the simple leaves of the seedling, except in size and the fact 

 that the fifth leaf is very broad basally. The sixth and seventh leaves are abnormal 

 (a common feature in suckers) , being very large, ii'regular in outline, and each having 

 one lateral leaflet. The ninth and tenth leaves are trifoliolate and near enough to l)e com- 

 parable to trifoliolate leaves of the seedling. In the Shag-bark, therefore, we find a 

 repetition of nepionic characters in suckers and partially in the trifoliolate terminal 

 leaves of branches. 



Trifoliolate leaves at the tips of the branches of adults as in the Shag-bark have also 

 been observed as characteristic of the Pig-nut, Hicoria glabra (Mill.) Bi'itton, and the 

 Mockernut, Hicoria alba (L.) Britton. 



QuERCUs ALBA. In the White Oak (Quereus alba L.),tlie seedling (PI. 20, fig. 62) 

 has a long, stout, flexuous root. The cotyledons remain in the acorn, buried just beneath 

 the surface of the soil. The stem is bare for a considerable distance, the first leaves not 

 developing, but axillary buds are prominent, as represented in the figure. The first 

 leaf is ovally rounded, slightly sinuous ; in seedlings this leaf is sometimes more or less 

 sinuous than in the first leaf of the specimen figured. The second and third leaves of 

 the specimen figured are gently lobed, and succeeding leaves in older specimens rapidly 

 take on a more deeply lobed character, until they make some approach to the form of the 

 leaves of the adult (PI. 20, fig. 64) . These early leaves are smooth, and deep green, as in 

 the adult. In suckers from the base of the White Oak the first formed leaves are more 

 or less ovate and slightly sinuous in outline (PL 20, fig. 63). They are variable, but the 

 sucker figured represents a fair average specimen. Later formed leaves rapidly take 

 on mature characters, as indicated by the lobation of the third leaf in the sucker figured. 

 In the adult, on weak shoots, leaves are frequently seen which are simple in outline as in 

 the sucker and seedhng, indicating localized reversionary characters. 



QuEROUS MINOR. Of the Post Oak [Quereus minor (Marsh) Sarg.) I have not seen 

 seedUngs, but suckei's from the base of adults have ovate or obovate leaves Avith gently 

 wavy margins as in the specimen figured (PL 20, fig 65) . These early leaves have the 

 deep green, roughness, and leathery texture of adult leaves. During further growth the 

 later added leaves rapidly assume the lobed form of leaves of the species, which is very 

 marked in character (PL 20, fig. 66). 



QuERcus TiNCTORiA. The Black Oak (Qtiercus tinctor'ia Bar.) and Scarlet Oak 

 (Qiceroi.s coccinea Wang.) both occurred in the woods where the seedlings described were 

 collected. As these species ai'e so close, the seedlings with present knowledge cannot 

 under the circumstances be certainly referred to either species. The seedlings (PL 20, 

 figs. 67 and 68) have stout, flexuous roots, but not quite so markedly as in the White 



