222 The Ottawa Naturalist. [March 



This correlation of colors is of value to the breeder as it 

 enables him to make an examination of organs which are ex- 

 posed and still growing or in operation and thus to tell what the 

 color of the kernel will be. If it be desired to produce a hybrid 

 of a uniform color, say a light blue, the tassels or male organs 

 might be removed from those plants bearing light green glumes, 

 stamens and silks before the pollen is shed so that a race of a 

 pure color might be developed much more quickly. 



Norton cites an interesting case of coherital correlation in 

 oats. In hulled oats the spikelet produces from 1 to 3 flowers 

 while naked types produce from 3 to 7 flowers. Hybrids of these 

 two have been effected with a view to increasing the number 

 of flowers to a spikelet and still retain the hulled character, but 

 it was found that where as many as four flowers were produced 

 to a spikelet the kernel was invariably found to be naked. 

 The difficulty of breaking this correlation has here worked to 

 the disadvantage of the breeder so it will be seen that these 

 correlations are not always advantageous. The existence of 

 these coherital correlations seems to strengthen the theory of 

 the existence of unit characters in plants which theory is being 

 accepted by many of our leading biologists and breeders of the 

 present day. East has recently extended Webber's classifica- 

 tion and has discussed several groups not included in the above 

 arrangement. His dissertation on "The interrelation of parts 

 not homologous" is especially interesting. 



Morphological Correlafions :Vnder this class belong those 

 cases "where a variation in one character is the primary cause 

 for the variation in another character." An example of this 

 class is illustrated in work done b}^ Dr. Hopkins, of Illinois, in 

 improving certain characters in the corn kernel, notably the 

 oil and protein content. 



The germ of the corn kernel is richest in oil, therefore, the 

 larger the germ in relation to the rest of the kernel the higher the 

 oil content; the hard corneous substance of the kernel is richest 

 in protein, hence the larger the proportion of this substance to 

 the rest of the kernel the higher the protein content. 



At the Nebraska Station, Lyon conducted some tests with a 

 large number of samples of wheat with a view to determining 

 the relationship between the per cent, protein and the weight of 

 kernel. His results indicate that high protein kernels are smaller 

 and lighter and that plants producing kernels of high protein 

 content do not produce such high yields as do those producing 

 kernels lower in protein. This suggests to the breeder the futility 

 of breeding for high protein and high yields at the same time. 

 Medium yielding heads are also found to come from highest 

 yielding plants. 



