RESULTS OF SOFT-PORK INVESTIGATIONS, II 
11 
very close parallelism. In the case of rice polish and tankage, the 
refractive-index values run relatively low. It will be recalled that 
the grade limits for rice-bran and rice-polish feeding are lower than 
in most of the rations. This behavior indicates that factors other 
than the degree of unsaturation as indicated by the iodine number 
influence the refractive index and the firmness of the adipose tissue. 
The feeding of corn following peanuts to pigs of 100 pounds' initial 
weight causes a more rapid decline in the refractive index than in 
the iodine number. Since there is a general lack of agreement be- 
tween iodine numbers and gradings, in the case of this combination 
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Fig. 4. — Comparison of refractive-index and iodine-number values with respect to 
the firmness of the fat formed on different rations 
of feeds the failure of the two fat constants to follow a parallel course 
such as the other rations show may not have much significance. 
RESULTS OF THE INVESTIGATIONS 
CLASSES OF PIGS USED 
Initial weight has been recognized in these investigations as a 
factor of importance enough to require control in connection with 
the various experiments. Therefore, in the plans of the experi- 
ments initial-weight limitations have been specified. Conditions 
have made it impossible to adhere strictly to these in all cases, but 
they have been followed without deviation in groupings and study of 
