84 Clyde E. Leightt 



Average weight of culm per plant. — This was obtained by dividing the 

 total weight of plant, obtained as described above, by the number of 

 culms per plant. The average weight of culms as herein used is often 

 identical with the total weight of plant, this occurring when a single 

 culm forms the plant. 



Number of kernels 



This was obtained by counting the number of kernels produced by the 

 entire plant, or in some cases by each culm. The average number of 

 kernels per culm was obtained by dividing the total number per plant. 

 bj^ the number of culms of the plant. 



Number of spikelets 



This was obtained in the same way as was the number of kernels. 

 Number of kernels per spikelet of plant 



This was obtained by dividing the number of kernels per plant by the 

 number of spikelets per plant. 



Weight of straw 



Total weight of straw for the entire plant. — This was obtained by sub- 

 tracting the total weight of kernels per plant from the total weight of 

 plant. 



Total weight of straw per culm.— This was obtained by subtracting 

 the total weight of kernels per culm from the total w^eight of culm. 



Average weight of straw per culm of plant. — This was obtained by 

 dividing the total weight of straw per plant by the number of culms 

 per plant. 



Average weight of kernels per plant 



This was obtained by dividing the total weight of kernels per plant 

 by the number of kernels per plant. 



Diameter of straw 



This was obtained by measuring, in decimillimeters, by means of 

 calipers, the greatest diameter of the second internode below the head 

 of the most important culm of the plant. 



Breaking strength of straw 



This was determined for the internode measured above. The methoCi 

 employed was to cut a piece of straw to a length of eight centimeters, 

 using the part nearest the root. This piece was then placed across an 



