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1910] + CROCKER, KNIGHT, ROBERTS—PEG OF CUCURBITS 331 
Tom), as shown by the clinostat experiments where the coats 
are removed. It is also evident that results obtained without 
reference to the effect of contact of the coats cannot lead to a 
knowledge of the part played by the several factors in determining 
the lateral placement of the peg. 
EFFECT OF DEVIATION FROM THE VERTICAL POSITION 
As has been stated, Nox claimed that seedlings grown in a 
vertical position, with the radicle pointing downward, gave two- 
sided or ringlike pegs. He found, however, that a slight deviation 
from this position (8°5) produced only one-sided pegs. We ran 
humerous experiments on various varieties of cucurbits for the 
purpose of testing this statement. The results are tabulated in 
the accompanying table. ‘‘Vertical” in this table means that the 
seed was held so that the plane passing through the largest dimen- 
_ Sion of the seed was in a vertical position and the radicle was point- 
ing downward. Deviations from this plane were made by tilting 
the plane of the seed the number of degrees from this position that 
is recorded in the table. The tilting always exposes one face 
rather than the edge of the seed to gravity. The seeds were held 
in position by two pieces of cork lightly clasping them at the central 
tegion. The whole culture was grown in darkness in a spray, so 
that no contact of media was involved and no contact of coats 
except when specified. 
A glance at this table makes it very evident that it . furnishes 
no ground for Noxt’s conclusion that a deviation of over 8°5 
gives only one-sided pegs. Our extensive experiments make us 
unable to understand how he obtained such results. 
It is evident from the table that in every variety used the 
deviation from the vertical is far more effective in the lateral 
placement of the peg when the coats are intact than when they are 
Temoved at the tip. This is due to the fact that the arching is 
made much sharper by the coat contact, and the lateral placement 
is in turn furthered by the sharper arching. 
It is also noticeable that there is a great variation in the several 
Varieties in the effectiveness of the deviation for the lateral place- 
ment of the peg. In Big Tom it is most effective, while in Boston 
