Growth and variation in maize. 99 



Materials and Methods. 



The data for this work were collected during the summer of 1908. 

 At that time an ear-to-the-row test of sweet corn was conducted at 

 Farmingtou, Maine. The results of this test along with others have 

 already been published (Pearl and Surface, '10). At the same place, 

 data regarding the soil, fertilization and cultivation of the crop are 

 given, so that it will not be necessary to repeat them here. 



The corn used for the growth work was that described in the paper 

 referred to as Type I. This is a white, small kerneled corn, vei-y 

 desirable from the standpoint of the packers. It makes a fairly rapid 

 growth and matures fairly early. The plants are rather short, rarely 

 reaching a height of more than 160 centimeters. 



In 1908 the plot in which this corn was grown consisted of 

 100 rows of approximately 100 hills each. The rows were three feet 

 apart, and the hills 18 inches in the row. Each row was planted from 

 a single ear which had been selected in the field of the previous year. 

 These ears had been especially selected on account of early maturity 

 and in most cases because of a good yield of grain. This corn was 

 planted on May 19, 1908, and was harvested for seed on September 

 6 to 12, 1908. Three kernels were planted in each hill but as soon 

 as the plants were well started these were thinned to one stalk in order 

 to secure a uniform stand. 



For the gi-owth work three series of plants were measured as 

 follows: Sixty plants in each of two rows, Nos. 131 and 133^) were 

 selected for study. The third series consisted of one plant from each 

 of sixty rows viz., rows 101 to 160. Thus in the first two sets of 

 measurements all the plants, in each case, were the descendants of a 

 single mother ear. In the third set, sixty different mother ears were 

 represented. 



In choosing the plants to be measured no selection was practiced 

 except that the plant should appear normal and vigorous. Thus in 

 rows 131 and 133 the first sixty hills in each row were taken. In 

 rows 101 to 160 the third hill from the end of the row was taken 

 unless for some reason this hill appeared abnormal at the time the plants 

 were selected. As was to be expected various accidents occurred from 



') The rows in this plot were numbered from 101 to 200 inclusive. The numbers 

 used here are the same as those used in the paper referred to above. 



