EAMOSE INFLORESCENCE IN MAIZE. 19 



departing from the common form in the opposite direction from that 

 of the ramose variation. 



Although in a general way the Gordo type of staminate in- 

 florescence is dominant to the ramose form in the first generation 

 of the hybrid, the influence of the Ramosa parent can be detected 

 easily when the various parts of the inflorescences are measured. 

 The ears of the F^ were normal and without branches. 



In the second generation of these hybrids the plants segregated 

 into normal and ramose plants. Classified from the general appear- 

 ance of the tassel, approximately one-fourth of the plants were 

 ramose, supporting the results of previous investigations. Measure- 

 ments of the various parts of the tassel showed, however, that the 

 ramose segregates had undergone alterations, having retained par- 

 tially the characteristics of the Gordo parent, while conversely the 

 normal plants showed the effect of their Ramosa ancestry. 



In the ramose group the general appearance of the tassels showed 

 great variability. When the ears were harvested a similar range was 

 observed. Plants classed as ramose from the characteristics of the 

 tassel had ears without branches, although the converse of this was 

 not observed. Ears were obtained which ranged in an unbroken 

 series from typical ramose to those without branches. In a general 

 way these intermediate forms of ears were associated with a similar 

 intermediate condition of the tassel. An F3 was grown from two 

 open-pollinated ears, one without branches and the other with but 

 four branches, both having tassels which betrayed their Ramosa 

 parentage. The progeny of these plants ranged from typical ramose 

 to normal in respect to the ears, although most of the tassels were 

 intermediate between ramose and normal. 



Eighteen F^ progenies were grown from self-pollinated F3 plants 

 and showed that the diversity observed in the second and third gen- 

 erations was inherited. Two of the progenies produced only ears 

 without branches, but the Ramosa ancestry was apparent in the tas- 

 sels. These two progenies were both from unbranched ears. On the 

 other hand, the progeny of a self-pollinated ramose ear produced 1 

 typically ramose, 11 intermediate, and 4 unbranched ears. It remains 

 to be determined whether the modification of the ramose variation is 

 the result of introducing numerous modifying factors through the 

 Gordo parent, or whether the ramose character depends upon the 

 combination of multiple factors for intense expression, or whether the 

 true-breeding intermediate forms represent a series of multiple alle- 

 lomorphs. 



During the course of these experiments another ramose variation 

 has been found which is genetically identical with Gernert's varia- 

 tion, but this appeared three years earlier in the gardens of Mr. 

 J. M, Mack, at Fall Brook, Calif. In this strain an intermediate 



