Inheritance in the Higher Plants loi 



round them. There is a red color in the pericarp or hull of 

 the maize seed which is transmitted as a simple Mendelian 

 monohybrid when crossed with a variety in which the 

 character is absent, but the color de^•elops to its full extent 

 only in bright sunlight. When a black bag is placed over 

 the young ear the color does not develop at all, yet such a 

 colorless ear will transmit the color as well as if that ear had 

 developed in bright sunlight. One may easily see then 

 how he might be deceived in the classification of such indi- 

 viduals and thereby draw wrong conclusions regarding the 

 inheritance of the character. 



Though the example just given is one of latency of fluc- 

 tuation, it really consists in the character being partially 

 inhibited by absence of light. One may see from it, how- 

 ever, that there can be real latency of inhibition through the 

 influence of inherited factors that affect the development of 

 independent characters. 



We have hitherto considered characters that seem to be 

 transmitted independently of one another. Let us now 

 spend a moment in discussing characters that appear to be 

 either coupled or antagonistic to each other in their trans- 

 mission. Some very interesting results on this subject 

 have been obtained by Emerson (Fig. 43). There are 

 maize varieties which are red in both the pericarp of the 

 seed and the cob. W^hen one of these is crossed with a 

 variety in which color is absent in both the pericarp and 

 cob, the second hybrid generation produces three ears like 

 the colored parent to one ear like the white parent. One 

 might suppose that the color in pericarp and in cob was due 

 to a single gametic factor. This can hardly be the case, how- 

 ever, for there are varieties with red pericarp and white cob 

 and varieties with white pericarp and red cob. When two 



