36 



according to Mayr (/.f.), a specific gravity of 

 83, and so it is equal to any in America, which, 

 according to Sargent, has a specific gravity of 

 83 to 86. 



9. Carya amara, Nutt, Bitternut. 



Of this, which is less valuable in every direc- 

 tion than the former, there were in 1890 in 

 Prussia 45 acres, and in 1900 only 29*89 acres 

 left. Although easy to raise, the valueless wood 

 produced excludes it from further trial planta- 

 tions. 



10. Carya tomentosa, Nutt, Hickory, Mocker 



Nut. 



Of this tree species there were in 1901 in 

 Prussia still 19*35 acres planted up. It has been 

 as successful as was expected. 



11. Carya sulcata, Nutt, Big Shellbark Hickory. 



In 1890, in Prussia, 24 acres were planted, 

 and of these only 0*98 acres were left in 1901. 

 Further planting was given up. 



12. Castanea americana, Raf., American 

 Chestnut. 



Taking into account the smaller amount of 

 warmth required, compared to the indigenous 

 variety, this tree was tried recently in South 



