ACID-SOIL PLANTS—COVILLE 375 
was so strong that 5 of the 12 delicate and tender plants died within 
a few days. The remaining seven grew vigorously, with normal 
healthy color. On September 9, at the end of the season’s growth, 
the seven aluminum-sulphate plants had an average height of 814 
inches. Growth of the stems had stopped for the year, and the 
leaves were of the normal size for healthy seedlings of this age, and 
of a healthy green color, except a few that were beginning to show 
their autumn purpling. The plants were of substantially the same 
size and vigor as other plants of the same origin which had been 
grown in a naturally acid soil of peat and sand. <A typical plant 
treated with the sulphate is shown in the larger of the two figures 
in Plate 9. The small and sickly plant in Plate 9 is one of a lot 
of 24 plants having exactly the same history and treatment as the 
others, except that they received no application of aluminum sul- 
phate. On September 9, 1924, when the aluminum-sulphate plants 
were in a normal healthy condition, with an average height of 814 
inches, the untreatd plants that were still living had an average 
height of 3 inches. Their leaves were small, those on growing tips 
pallid, those a little older pink instead of green. Growth still con- 
tinued, in an abnormal and unseasonable manner, and very feebly 
and slowly. Three of the original twenty-four plants had died. 
On April 17, 1925, both lots of plants were repotted in 3-inch pots, 
in the same soil as before, and the lot that had received the first ap- 
plication of aluminum sulphate was given another application, four 
grams to each 38-inch pot. At the end of the season, after the 
leaves had dropped, the seven plants treated with aluminum sulphate 
were all strong and vigorous, with an average height of 15 inches. 
Of the 24 untreated plants all but eight were dead. These had an 
average height of 314 inches. The tips of all the stems were dead, 
the height of the live portion of the plants averaging only 21% inches. 
On March 31, 1926, both lots of these blueberry plants were again 
repotted in 4-inch pots, in neutral greenhouse soil as before. Each 
of the seven plants that had previously received the aluminum- 
sulphate treatment was given a new application of 8 grams. The 
ground sulphate was placed on the surface of the soil and each pot 
was watered four times, half an inch of water being applied each 
time. On the following day five additional waterings were given, in 
order to leach out any lime that may have been released, in the form 
of calcium sulphate, as a result of the application of the aluminum 
sulphate. 
On April 12, 1926, the seven aluminum-sulphate plants, all of 
which were healthy, and six of the untreated plants, all of which 
were sickly, were placed in a chilling frame at 35°-40° F. Both 
lots of plants had been in a warm greenhouse all winter and were 
completely leafless and dormant. A chilling was necessary to bring 
