58 PROCEEDINGS OF THE ACADEMY OF [Feb., 



Populus monilifera, Tilia americana, Magnolia conspicua, JEsculus 

 hippocastanum, Salix babylonica and Forsythia viridissima were placed 

 in various chemical solutions described below, and at the same time 

 plants near the University were observed under more normal conditions 

 out of doors. Twigs cut from these trees were placed in the chemical 

 solution on March 1, 1907. Under each species will be mentioned 

 the chemical solutions used and the reaction which took place. The 

 date of the reaction will be given in each particular case. The species 

 of the first year's experimentation are arranged in the order of their 

 response. The plants were kept in a greenhouse where the tempera- 

 ture range was about 25 degrees. At night the temperature descended 

 to 65° F., while on sunny middays it rose as high as 90° F. 



Forsythia viridissima. — The following chemical solutions were 

 used with this species. One per cent, chromic acid filled several of the 

 bottles; ordinary stock picric acid diluted four times with water; 

 ammonium nitrate (two grams) dissolved in 200 cubic centimeters of 

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

 water; five drops chemically pure nitric acid in fifty cubic centimeters 

 of water ; menthol water ; two bottles filled with 800 cubic centimeters 

 of filtered water; two grams ammonium sulphate in 600 cubic centi- 

 meters of water; 100 cubic centimeters of ether in 500 cubic centimeters 

 of water ; 200 cubic centimeters of chemically pure ammonium hydrate 

 in 1,000 cubic centimeters of water; a saturated solution of corrosive 

 sublimate in 1,000 cubic centimeters of water; ten drops of chemically 

 pure hydrochloric acid in fifty cubic centimeters of water. 



One week after the experiments were begun buds of this species 

 showed a reaction. The most marked was with the ammonium 

 hydrate solution when, on March 8, it was found that all of the buds 

 above the middle ones were well opened, but the leaves remained 

 tightly folded. There was a steady advance in this solution until 

 March 20. On March 11 the flower buds were ready to open, and 

 on March 15, four days later, the buds were expanded, while on March 

 18 the flowers had withered and a few green leaves had appeared. 

 After March 25 there was no advance, and on March 28 the twigs were 

 dead. Response was shown on March 8 by the twigs in picric acid, 

 ammonium nitrate, sodium chloride, hydrochloric acid, ammonium 

 sulphate, ether water, corrosive sublimate and pure water. The 

 most marked response was in the solution with five drops of hydro- 

 chloric acid, where the buds had burst, and in the picric acid, where 

 the three topmost buds had burst. The response in the other cases 

 was shown by an easement of the buds. In the pure water the buds 



