No. 535] NOTES AND LITERATURE 



421 



determination of statistical correlations between different parts 

 of the maize plant might be of use to the practical breeder. The 

 general conclusion to which the author comes in regard to this 

 point is as follows : 



Considerable study of the subject has forced upon the writer the be- 



practical breed in- There are rare eases in which the coupling of unit 

 characters may aid the breeder in making selections at an early period. 



The correlations studied were those of weight of grain per 

 plant (measuring yield) with each of the following characters: 

 (1) Diameter of stalk, (2) length of leaf, (3) breadth of leaf, 

 (4) height of mature plant, (5) height of seedling, (6) number 

 of internodes, (7) average length of internodes, (8) percentage 

 of internodes below the ear, (9) length of ear at appearance of 

 silks, (10) date of appearance of tassel, (11) date of appearance 

 of pollen, (12) date of appearance of silks, (13) duration of 

 flowering period (pistillate flowers) in days, (14) number of 

 branches in the tassel. 



They are thus statistically significant. In view 'of this fact the 



cases the coefficient^' correlation is so small that it is pr„hably 

 not worth while to try to classify it or even to conclude that there 

 is correlation," seems not to have been very well considered. The 

 same criticism is to be made against the paper of Clark discussed 



though absolutely small. 



The garden pea (Pisum sativum) has been the subject of 

 several recent biometric studies. At the Massachusetts Station 



