16 T. L. Lyon anv J. K. WILson 
had developed and passed thru the agar to the bottom of the glass tube, 
the plantlets were transferred. The tube (fig. 1, e), with agar and plant- 
lets, was lifted out of the test tube and set into the mouth of the prepared 
flask. This was accomplished with sterile forceps. 
PREPARATION OF THE FLASKS 
The flasks used were in most cases of 8-liter capacity, altho some held 
12 liters. As mu¢h of the nutrient solution was put into each flask as 
could be sterilized. A piece of cloth was stretched over the mouth, and 
a hole just large enough to permit the insertion of a piece of tubing from 
28 to 30 millimeters long (fig. 1, c) was cut in the cloth. This tubing (c) 
was just large enough to allow the plant and its tubing (e), described above, 
to telescope into it. 
The lower end of the tube (c) was slightly constricted, to prevent the 
inner tube (e) with the plant from going too far into the flask. Enough 
cotton (6) was wrapped around the tube to hold it firmly in place when 
it was pushed into the mouth of the flask. The upper end of the tubing 
was adjusted so that it came about even with the top of the flask. The 
lower end extended below the cotton and the cloth (a), so that when the 
flask was full of liquid the liquid would just touch the tubing but not the 
packing. Each flask was then covered with a large beaker. The inverted — 
beaker was large enough to leave some space for the growing plant. | 
Since there was need for more solution in the flask than could be sterilized — 
in it, an extra amount was prepared which could be poured thru the 
opening that was left. | 
| 
NUTRIENT SOLUTION 
The nutrient solution had the following composition: 
Calcium nitrate, Ca(NO3)2.+4H,0............ 2.70 grams 
Magnesium sulfate, MgSO.1+7H.2O........... 0.60 gram 
Pocassiumarc iil orien © lise een ee 0.75 gram 
Potassium dihydrogen phosphate, KH:PO,... . 1.50 grams 
Rerricysullate: Shen(S@s)oe erate en a ee 0.05 gram 
Distilled water topmakey- 39 eae 1000 cubic centimeters 
This was designated as the full nutrient solution. In most cases of actual 
use it was diluted to ten times this volume. In earlier work it had been } 
noted that certain plants, especially maize, tend to become chlorotic | 
