66 PROCEEDINGS OF THE ACADEMY OF [Feb., 



nal bud fully expanded. March 28 : The twig was found dead, because 

 the water had evaporated from the jar. 



Corrosive Sublimate. — March 15: Bud scales eased. March 18: 

 Buds nearly all burst. March 20 : Half of the folded green leaves seen 

 in the partially open bud. March 25 : One to three leaves were found 

 fully expanded. March 28: All of the buds were burst, with one to 

 three leaves fully expanded, flat and large. April 1 : Twigs gone bad. 



Quercus paltjstris. — The chemicals used were: Two grams of 

 ammonium nitrate dissolved in 200 cubic centimeters of water ; five 

 decigrams of sodium bicarbonate dissolved in fifty cubic centimeters 

 of water; five decigrams of sodium chloride dissolved in fifty cubic 

 centimeters of water ; 200 cubic centimeters of chemically pure ammo- 

 nium hydrate dissolved in one liter of water; saturated solution of 

 corrosive sublimate in one liter of water; two water control experi- 

 ments were inaugurated. 



The twigs placed in the ammonium nitrate, sodium bicarbonate, 

 sodium chloride, ammonium sulphate, and ammonium hydrate solu- 

 tions made no response by the opening of the buds. Those, however, 

 in the solution of corrosive sublimate showed signs of response on 

 March 25, when the terminal bud showed signs of elongation. On 

 March 28, three days after, the terminal bud had burst and the leaves 

 were ready to unfold. On April 1 the twigs began to show signs of 

 going bad. In water the response was more marked than in the corro- 

 sive sublimate solution, for on March 25 the terminal bud had burst, 

 but the leaves were still enclosed in the stipular scales. On March 28 

 the leaves had nearly expanded, and on April 1 the leaves were fully 

 expanded and the new shoots 100 to 127 millimeters long. 



Summary of the Experiments of the First Year. 



The experiments conducted the first year with twigs in various 

 solutions throw considerable light upon the conditions which influ- 

 ence the flow of sap in plants. Strasburger set the cut ends of trees 

 in tubs containing copper sulphate solution. He found that the 

 poison ascended to the leaves a distance in the tallest trees of twenty- 

 one meters. If such a violent protoplasmic poison ascends the trunks 

 of trees, it is clear that they must kill all of the cells lying in the path 

 of its ascent. Strasburger concluded that the living cells of the stem 

 were not necessary to the ascent of the sap, as a result of the above- 

 mentioned experiment with copper sulphate. Strasburger also killed 

 portions of the stems of living trees by heat, and yet the upper living 



