(28) 



2. In a population, the coefficients of correlation show 

 that variations in spine niimber, shell size and mouth size 

 are strongly inherited, while variations in shell form and 

 mouth form are weakly inherited. 



3. In a single clone, the coefficients of correlation 

 show that variations in spine number and shell size are 

 probably inherited, 



4. If a diminishing ancestral correlation is considered 

 a criterion of inheritance of variations within a clone, 

 the coefficients of correlation of the population give 



such evidence of inheritance for all the characters studied, 

 and the coefficients of correlation within a clone give 

 such evidence for spine number and shell size. 



5. From the evidence adduced iinder 2, 3 and 4 above, it 

 was concluded that variations in spine number and shell size 

 are inherited within the clone. Since shell size might be 

 "inherited" without the mediation of the nucleus, spine 

 number was considered the most favorable character for use 

 in selection experiments. 



The results of the experiments in the selection of 

 variations in spine number may be summarized as follows. 



6. In the brief experiments 1 and 2, mass selection based 

 on external appearance gave contradictory results in two 

 different races. In explanation of this, it is assumed 

 that in different races the degree of correlation between 

 the external appearance of the individual and its genetic 

 constitution is diverse; in some the two are highly cor- 

 related, in others but little. 



