50 



GENETICS IN RELATION TO AGRICULTURE 



The character of yield is now to be considered in relation to the number 

 of culms per plant. Hence there will be nine rows and seven columns 

 in the correlation table. The class values are indicated in consecutive 

 order beginning usually at the upper left-hand corner. In the present 

 instance, oat plant No. 1 yielded 0.5 g. and had 2 culms, hence this plant 



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FIG. 21. To illustrate transference of data from original record to correlation tablo. 

 V x indicates class values for total yield of plant, V v , number of culms per plant. 



is tallied in the upper left-hand square of the table; plant No. 2 yielded 

 2.5 g. and had 3 culms, it is tallied in row 3 column 2, and so on throughout 

 the list of 400 plants. Then the tallies in each square are counted, re- 

 corded and transferred to a new table drawn on a smaller scale for future 

 use, the original table being filed as a permanent record. In this way 

 the tables shown in Figs. 22 and 23 were prepared. 



Interpretation of the Correlation Table. A correlation table is a 

 record of the frequency distributions for two different characters so 

 arranged as to show the tendency, if any exists, for one character to 



