78 BULLETIN OF THE BUSSEY INSTITUTION. 
I. The outer skins were removed from a number of kernels of 
pop-corn (the variety known as rice-corn) and attempts were 
made to pop them, but without success. On being heated, the 
skinned kernels merely swelled to a slight degree, but they did 
not burst. 
II. Kernels that had not been skinned were cut in two, cross- 
wise of the length of the kernel, and the half kernels thus 
obtained were subjected to the test of popping. It appeared 
at once that those halves of the kernels which in their natural 
state lay nearest the cob did not pop when heated, while the 
outer halves of the kernels popped readily. When the skin was 
removed from the kernels before cutting them in two crosswise, 
neither the outer nor the inner halves of the kernels could be 
made to pop. 
III. Halves of kernels that had been cut lengthwise into two 
parts popped readily in some of the trials, and it did not appear 
in this case that the popping was confined to any particular part 
of the kernel. 
IV. Some unskinned kernels of pop-corn were eut in two 
lengthwise, and the long half kernels thus obtained were cut in 
two crosswise, so that each kernel was divided into four quarters, 
and attempts were made to pop these pieces. It was found that 
none of the quarters from that end of the kernels which had lain 
next the cob would pop, while some of the quarters from the 
outer end of the grain were popped successfully, although other 
specimens would not pop. It did not appear, however, that 
there was any difference, as to popping, according as the quarter 
kernels came from one or the other side of the pointed end of the 
grain. The difficulty seemed to be that so large a portion of the 
surface of these fragments (quarter kernels) was practically 
denuded that there was not skin enough left to help out the act 
of popping. 
V. Several kernels of pop-corn were cut in halves, crosswise, 
the pieces were soaked in ether during five days and then dried 
for an hour or two at 100°C. On being heated, those halves 
which came from the outer, pointed end of the kernels popped 
successfully, while none of the halves from the inner end of the 
kernels would pop. ‘They merely swelled a little. 
