392 BOTANICAL GAZETTE [MAY 
Procedure 
Spring wheat of the Marquis variety was germinated on a net 
as described by Sutve (15). Seedlings carefully selected for uni- 
formity of size and vigor were transferred, when about 5 cm. tall, 
to SHIVE’s three-salt solution R;C,, after having been mounted in 
the double piece paraffined cork stoppers devised by ToTTINGHAM 
(18). The stoppers were of the proper size to fit quart fruit jars 
of colorless glass, which were used for culture vessels. Three 
seedlings were included in each culture. The cultures thus pre- 
pared were conducted during a time period of twenty-five days, 
with renewal of solutions every three or four days. When the 
seedlings were approximately thirty days old from the time of 
germination, cultures were selected in which the plants were 
about equal with respect to size and vigor in so far as this could be 
judged from careful observation. The plants of the selected 
cultures, without being removed from the cork stoppers in which 
they were mounted, were then taken from the three-salt solutions, 
the roots were washed by carefully dipping them several times into 
distilled water, allowed to drain, and were then placed in the 
nutrient solutions devised by the various authors. The glass jars 
to which the plants were transferred were like those from which 
they were removed. Each jar had a capacity of goo cc. 
The formulae of the nutrient solutions devised by the various 
authors are given in tables I and II in terms of gram-molecules pert 
liter. The solutions made up according to the formulae in table I 
were corrected to a total osmotic concentration value of approxi- 
mately 1.75 atmospheres by the method of the freezing point 
lowering, while those prepared according to the formulae in table II 
were similarly corrected to an approximate osmotic concentration 
value of 1.00 atmosphere. No iron was added to any of these 
solutions, except to those for which this element is mentioned in 
the formulae. The solutions devised by BrrNER and Lucanvs (1), 
Crone (2), and Sacus (13) contained precipitates. In making the 
cryoscopic tests for the total osmotic concentration values of these 
solutions the precipitates were allowed to settle, after which 
samples of the supernatant solutions were drawn off by means of a 
pipette, the lowering of the freezing points determined, and the 
corrections made whenever necessary. 
