7O PEAS AND PEA CULTURE 



years to fix the type of a new variety, for during 

 the first half dozen years a new sort is apt to be 

 unsteady and uncertain as to its character." 



Some comprehensive and interesting experiments 

 in breeding of peas were undertaken at the Massa- 

 chusetts experiment station by Pomeroy in 1907. 

 The work has been continued ever since, and is 

 now in charge of Professor Shaw, who in July, 1909, 

 wrote as follows : " We are aiming at some definite 

 data regarding heredity, variation and correlation. 

 The characters studied are vine length, number of 

 pods per vine, pod length, number of peas per pod, 

 and the total number of peas per vine. We aim 

 to keep an exact record of the descent of each plant, 

 and examine into the correlation of these factors in 

 each generation, and in what degree they are trans- 

 mitted to succeeding generations. The amount of 

 variation of each factor in each generation is also 

 carefully considered. The methods used are some- 

 what technical, being worked out by Galton and 

 Pearson in England. Results so far are not very 

 conclusive. The work was started as a sort of side 

 issue, and last year developed great interest. One 

 or two distinctive strains have appeared, probably 

 because of mixed seed at the start. The descend- 

 ants of different plants show marked differences, 

 and are remarkably uniform among themselves. 

 Probably the fact that peas are very generally self- 

 fertilized accounts for this fact. The puzzling thing 

 that appeared last year was the occurrence of one 

 or two negative heredity coefficients, but this de- 

 mands further investigation before much depend- 

 ence can be placed in it." 



