1gto] CROCKER, KNIGHT, ROBERTS—PEG OF CUCURBITS 327 
kin called Big Tom, especially when grown on the clinostat, gives 
a somewhat higher percentage of strong arching in response to coat 
contact than does the Hubbard squash. Fig. 2 shows all the 
individuals of a culture of Hubbard squash grown as described 
above, coats removed at tip, and radicles pointing downward. 
Of the 26 seedlings, none are sharply arched, and all have pegs 
either two-sided or ringlike. Three show slightly more prominent 
pegs on one side than on the other. It is evident then that in 
Fic. 3—Crop of Hubbard squash as in fig. 2, but coats not removed at tip; shows 
sharp arching induced by contact of coats. 
the Hubbard squash little arching and no one-sided pegs are pro- 
duced if the seedlings grow with the radicles pointing vertically 
downward, and with no contact of either coat or media. Fig. 3 
Shows a similar culture except that the coats were intact during the 
gtowth. Of the 42 seedlings, 29 are sharply arched and 13 very 
slightly or not at all. This shows contact of coats to be very potent 
in arch-production. Of those that are sharply arched, 8 have 
Pegs entirely on the concave side of the arch, while several others 
show the greater peg-development on that side. In this case the 
arching is against gravity, which emphasizes the potency of con- 
