Ill U.S. 



PUBLIC DOCUMENT — No. 33. 



65 



Y ai i r at i o x i x Peas. 



C. S. POMEROY. 



Two new ideas, of the magnitude of great discoveries, re- 

 cently brought to the front in the scientific world have devel- 

 oped an entirely new interest in plant breeding. This new 

 interest has manifested itself both in practical plant-breeding 

 work and in renewed scientific investigation. The two ideas 

 here referred to are : (1) Mendel's law, so called ; and (2) the 

 statistical method of studying variation and heredity. 



The horticultural division of the Massachusetts Agricultural 

 Experiment Station has been engaged for several years in cer- 

 tain investigations in both these fields. On account of the 

 length of time required to secure definite results, no report has 

 yet been made of these experiments, but a brief report of some 

 of the partial figures may be of interest at this time, particularly 

 by way of illustrating the modern methods of study. 1 



For the purposes of this particular study, one row of peas 

 was staked off in the- middle of a field. A careful record was 

 kept of each vine, showing its length, the number of pods 

 borne, the length of the pods and the number of peas in each 

 pod. The variation is shown by the following figures : — 



i The statistical methods of study and graphic, methods of presenting data have been 

 developed especially in England by Francis Gallon and I'rof. Karl Pearson. In this coun- 

 try the same methods have been presented by C. B. Davenport and by E. Davenport, dean 

 of the Illinois College of Agriculture, in his recent boolf, "Principles of Breeding." It 

 seems better to refer the student of plant breeding to these works, rather than to attempt a 

 more extended explanation of these somewhat complicated methods in this report. 



