SKINNER AND BEATTIE: EFFECT OF ASPARAGIN ON WHEAT 437 
It would seem that chemical control under as normal conditions 
as a cultural experiment will allow, is better than conducting the 
experiment under the artificial condition of sterility, which, after 
all, is made only so that biochemical changes may be excluded. 
In these experiments the bottles were sterilized before being used 
in making culture solutions for the various changes, the pans and 
other apparatus used in germinating the seed were sterilized from 
time to time, and corks used for the cultures were always clean 
and sterilized before use. Although all of these precautions 
were taken, it was of course not possible to exclude some micro- 
organisms in such work, as the solutions were exposed from time 
to time to the air. There was no excessive microorganic life 
noticeable. While bacteria and other micrcorganisms were 
present in the solutions to a slight extent, it can hardly be said 
that their influence could have been large; that is, such influence 
as they had was probably so slight as to be negligible so far as the 
general and larger tendencies which are shown to exist are con- 
cerned. 
While the effect of the asparagin decreased with increasing 
nitrate so far as additional effect on growth is concerned, it had 
nevertheless a conserving effect upon the amount of nitrate left 
in the solution during the time the plants were growing, as is 
shown by the analysis of the solution. It appears, therefore, that 
the plant can utilize this nitrogenous compound for plant syn- 
thesis. 
BurEav oF Sorts 
Wisemcron. D.C. 
Explanation of plate 33 
Wheat as growing in culture solutions with and without asparagin, and 
oe S proportions of potash and phosphate but no nitrate. Cultures 
with the Ne z following the sie contain asparagin. 
