CORRELATION AND HOMOLOGY. 



29 



The results shown in table 12 are very regular. In every case the 

 correlation is greater between the homologous joints than it is between 

 the non-homologous, though some of the differences are absolutely small. 

 The figures in the "excess" column show the relative significance of 

 these differences in comparison with their probable errors. These fig- 

 ures are the values of the ratio Difference/Probable error of difference. 

 Taking into consideration the values of this ratio in the different cases 

 and also the fact that in every case the difference is in the same direction, 

 it is clearly justifiable to conclude that there is a uniform and definite 

 tendency for the meripodite of any leg to be more highly correlated with 

 the homologous segment (i. e., the meripodite of a second leg} than with 

 any other segment of that second leg. It is, of course, to be understood 

 that this statement is made only for those legs and joints studied in this 

 work. 



We may turn next to the carpopodite correlations (table 13), treating 

 the data in the same way. 



TABLE 13. 



(A) CAKPOPODITES OF LEG I AND II, AND II AND III (CONTIGUOUS METAMERES). 



