The Migration of Our Forest Trees. 201 



Bitter Hickory (Hicoria ininiina (Marsh.) Britt.) is common in 

 the forests of the Missouri river valley, from which it has heen carried 

 northward into the southeastern counties of Nebraska from Richardson 

 to Pawnee, Lancaster and Cass. 



Oaks (Qiiercus spp.). The fruits (known as "acorns") are thin- 

 and tough-shelled nuts, each containing a single, large, edible seed. 

 They are relished by squirrels and other rodents, as well as by swine, 

 cattle and sheep, and also by deer and buffaloes. All of these no doubt 

 have contributed in some degree to their dissemination, but the squirrels 

 have been the most active agents in this work, gathering and hiding 

 them in many places, usually at some distance from the parent tree. 



White Oak (Quercus alba L.) is common in the Missouri forests, 

 from which it has been carried into southeastern Nebraska as far north 

 as Cass county. 



Post Oak (Quercus minor (Marsh) Sarg.) is found in the Mis- 

 souri forests, from which it is reported to have moved northward into 

 southeastern Nebraska (Sargent). 



Bur Oak (Quercus macrocarpa Michx.) is abundant in the Mis- 

 souri river valley forests, from which it has migrated along the river 

 valleys fully half way across the state, reaching Harlan county on the 

 south, Custer county in the centre and Cherry county on the north. It 

 occurs, also, in the Black Hills of South Dakota, to which it was proba- 

 bly brought from the same Missouri forest area. 



Yellow Oak (Quercus acuminata (Michx.) Sarg.), found in the 

 Missouri forests, has reached the Platte river in eastern Nebraska. 



Low Yellow Oak (Quercus prinoides Willd.) of the Missouri for- 

 ests has barely reached southeastern Nebraska in Richardson county. 



Red Oak (Quercus rubra L). is common in the Missouri forests, 

 from which it has been carried northward along the Missouri river to 

 Dixon county and westward fifty or sixty miles. 



Scarlet Oak (Quercus cocciuea Muench.) occurs in the Missouri 

 forests, and has entered the southeastern counties of Nebraska from 

 Richardson to Cass. 



Black Oak (Quercus velutina Lam.) is found in the Missouri for- 

 ests, from which it has moved northward along the eastern border of 

 Nebraska to the Platte river. 



