72 PROCEEDINGS OF THE ACADEMY OF [Feb. r 



each station are given in the accompanying table. It will be seen 

 that the material came from as far south as Alabama and as far north 

 as Massachusetts, and that the twigs sent by the correspondents were 

 abundant enough to represent, in many cases, the entire geographic 

 range of the variety studied. Thus the Red Astrachan apple twigs 

 came from Pennsylvania State College; College Park, Maryland; 

 Geneva, New York; Storrs, Connecticut, and Auburn, Alabama. 



Bundles of twigs were sent by express in boxes or protected by bur- 

 lap. Upon their receipt at the University they were kept in a light, 

 cool, airy cellar until all of the packages had been received. The 

 experiments, as far as practicable, were started at the same time,. 

 viz., on the afternoon of January 22, 1908, and on the morning of 

 January 23, 1908. The bottles with chemical solutions had been 

 prepared previously. The jars with the twigs were placed in a green- 

 house the temperature of which ranged from about 70° F. at night to 

 90° or 95° in the daytime. The latter temperature was reached with 

 a bright midday sun. The observation continued uninterruptedly 

 from January 23, 1908, to March 14, when the experimentation vir- 

 tually stopped. Only one change was made in the fluids, viz., on 

 February 14, 1908, when the evaporated water was resupplied, without 

 the addition of any fresh chemical substance. 



The chemical solutions used were made as follows: 



Corrosive sublimate. — Strong solution : Ten grams in 850 cubic centi- 

 meters of water. Weak solution: Five grams in same amount of 

 water. 



Copper sulphate. — Strong solution: Ten grams in 850 cubic centi- 

 meters of water. Weak solution: Five grams in same amount of 

 water. 



Sodium chloride. — Strong solution: Ten grams in 850 cubic centi- 

 meters of water. Weak solution: Five grams in same amount of 

 water. 



Ammonium nitrate. — Strong solution : Ten grams in 600 cubic centi- 

 meters of water. Weak solution : Five grams in 600 cubic centimeters 

 of water. 



Ammonium oxalate. — Strong solution: Ten grains in 600 cubic 

 centimeters of water. Weak solution : Five grams in same amount of 

 water. 



Ammonium oxalate. — Strong solution: Ten grams in 600 cubic centi- 

 meters of water. Weak solution: Five grams in same amount of 

 water. 



Potassium chloride. — Strong solution : Ten grams in 900 cubic centi- 



