1909.] 



NATURAL SCIENCES OF PHILADELPHIA. 



91 



Copper sulphate (strong). — No response shown in twigs from the 

 University of Pennsylvania; College Park, Maryland; Ithaca, New 

 York. 



Copper sulphate (weak). — Amherst, Massachusetts: Leaf buds eased 

 February 1; leaf buds burst February 4; all leaves withered February 

 14. 



Sodium chloride (strong). — No response in twigs from University 

 of Pennsylvania and Ithaca, New York. College Park, Maryland: 

 Leaf buds eased February 3 ; leaf buds burst February 7. 



Sodium bicarbonate (weak). — Amherst, Massachusetts: Leaf buds 

 eased February 5; leaf buds burst February 7. Lafayette, Indiana: 

 No response. 



Potassium bisulphate (strong). — New Brunswick, New Jersey: 

 Leaf buds eased January 31; leaf buds burst February 1. 



Potassium bisulphate (weak). — Amherst, Massachusetts: Leaf buds 

 burst February 5. Lafayette, Indiana: No response. 



Acetic Acid (strong). — New Brunswick, New Jersey: Leaf buds 

 eased January 31 ; leaf buds burst February 1. 



Acetic Acid (weak). — Lansing, Michigan: Leaf buds burst January 

 30; first leaf unfolded February 1; all leaves unfolded February 4. 

 No response of twigs from Lafayette, Indiana, University of Penn- 

 sylvania, Ithaca, New York, New Brunswick, New Jersey, in ammo- 

 nium nitrate (strong), weak ammonium nitrate, strong and weak 

 ammonium oxalate, weak and strong potassium chloride and strong- 

 sodium bicarbonate. 



Water. — 



Leaf buds eased 



Leaf buds burst 



First leaf unfolded... 

 All leaves unfolded... 

 First leaf withered... 

 All leaves withered... 



Univer- College 

 sityof | Park, 

 Penna. ! Md. 



New 

 Brims- Ithaca, Geneva, 



wick, 

 N.J. 



N. Y. i N. Y. 



Lans- 

 ing, 

 Mich. 



Am- 

 herst. 



Mass. 



Jan. 31. Feb. 4. Feb. 1. Feb. 3. 



Feb. 5jFeb. 3. Feb. 28. Jan. 29. 



Feb. 3.|Feb. 8. Feb. 8. Feb. 1. Feb. 7. 



Feb. 4. Feb. 11 Feb. 8. 



Feb. 11. Feb. 14J Feb. 14. 



Feb. 14. Feb. 18. Feb. IS. 



The twigs from Amherst, Massachusetts, further showed the ease- 

 ment of the flower buds on January 29; burst on January 31; were 

 open February 4 and withered by February 5. 



Pin Oak (Quercus palustris).- 



