20 



were taken as it was believed that such heads or panicles offered greater 

 possibilities than did those borne on the lateral and usually less perfectly 

 developed shoots or "stolons." 



The chosen heads were then weighed, it being believed that the heavier 

 the head the larger the kernel and the greater the yield. When the heavy 

 heads had been selected, the next step was to choose those which contained 

 the greatest number of spikelets as it was thought that this was directly 

 correlated with yield. Since long open heads of wheat, barley or rye often 

 produce actually fewer spikelets than the short more compact type and 

 since the latter type was thought to be correlated with stiffness of straw a 

 system by which the specific density of a head, or the number of nodes per 

 100 m.m. (3.9") could be expressed, was devised. By this system, the 

 density of the different heads could be expressed in figures and another 

 important basis of selection thus established. The manner in which this 

 system was applied may be explained more clearly by setting the following 

 problem thus : 



A head of wheat measuring 130 m.m. in length has 24 nodes containing 

 70 kernels. Problem: What is the density (number of nodes in 100 m.m.) 

 of this head and the number of kernels per 100 m.m.? 



Answer : 



In 130 m.m. there are 24 nodes 



24 



" 100 " - x 100 = 18 nodes. Specific density == 18 



130 



(This was commonly expressed as 

 "D. 18"). 



In 130 m.m. there are 70 kernels 



. 



" 100 " x 100 = 54 kernels. 



130 



In order that the density of a large number of heads might be quickly 

 determined, Neergaard devised the first automatic classificator used at Svalof . 

 This obviated the necessity of working each case out on paper as above. 



The choice of heads having been effected, the next step was to choose 

 the best kernels. In accordance with the old idea that these were to be 

 found near the centre of the head in wheat, barley and rye, and in the upper 

 part of the panicle in oats, only kernels from these places were taken for 

 seeding. 



The use of sound, plump and large sized kernels for the sort was insisted 

 upon. The importance of this practice has never been challenged. 



A further selection of kernels was sometimes made on the basis of 

 quality, an expression of which was sought by means of the " Diaphanoskop," 

 an instrument which made it possible to compare the " mealiness " of different 



