(18) 



small that no definite conclusions one way or the other 

 can be drawn from them. As a glance at the table will show, 

 they give no evidence for the inheritance of variations 

 within the clone. Mary of the coefficients, in both gene- 

 rations, are negative, hardly any are large enough to be 

 significant, and in the few cases where there is a dim- 

 inishing ancestral correlation, it is probably due to chance 

 alone. One thing, only, is worth noting. The coefficients 

 for spine number, in both generations, are all positive. 

 This fact has no significance by itself, but, in compari- 

 son with the conditions shown by all t?ie other characters, 

 it may be considered to support the conclusion that vari- 

 ations in spine number may be inherited within the clone. 



To sum up the purely biometrical part of the work, we 

 may say- 



1. Diverse clones exist in Centropyxis. 



2. Within a population, diversities in size of shell and 

 mouth, and in spine number are decidedly inherited, while 

 diversities in form of shell and mouth are only slightly 

 inherited , 



3. 'iVithin single clones, the evidence from coefficients 

 of correlation indicates that variations in shell size and 

 spine number are inherited. The evidence that variations 

 in the other characters are inherited is weak or lackirg. 



It was now decided to choose a single character for 

 intensive study of the effect of selection. The statis- 

 tical work has eliminated the two form characters, as 

 showing only slight correlation even in a population. 



