Johnson—Pyloric Caeca of the Centrarchidae. 719 
Micropterus salmoides Lacepede. 
The relation of the viscera of the wide-mouthed black bass 
is shown in Plate XLII, Figures 22-25. It has the caeca 
branched. Holbrook says of these: “There are eleven primi¬ 
tive caecal appendages, which soon divide into two or three 
others so that as many as twenty-eight may at times be 
counted.” The bases of these branched caeca varied from 9- 
13. The mode was 10-11. (Text-figure 1). Text-figure 2 
shows the distribution of branches to each tip. The mode was 
2, mean 2.7346 ± .0267. The standard deviation was .9166 ± 
1 8 -3 4 5 6 7 6 9 0 
Text-Figure 2. 
Frequency polygon of the numbers of tips to o35 caeca in 51 indi¬ 
viduals of Micropterus salmoides. 
Ordinate—Number of specimens. 
Abscissa—Number of tips to each caecum. 
.0177, and the coefficient of variation extraordinarily high, 
33.5186. This high variability may indicate that the branched 
condition is relatively new and not yet fixed. This seems 
likely, because this is the only species of the genus having 
branched caeca. The distribution of these tips according to 
the position of the several bases is shown in Plate XLIV, 
Figure 8, where the numbers are averaged in individuals hav¬ 
ing ten bases. The greatest branching takes place where there 
