June ii, 1917 
Hybrids of Zea ramosa and Zea tunicata 
389 
This abnormality is similar, if not identical, with an abnormality 
discovered by Blaringhem (1907) in a strain of Z. tunicata and termed 
by him “cauliflower.” To judge from Blaringhem’s description and 
plates, the chief differences between his specimens and ours—and these 
may be only of degree—are that in his examples the disturbance did 
not extend to the entire inflorescence, and the ultimate ramification 
terminated in microscopic floral organs, while in ours no sign of floral 
organs was developed. 
Before an examination of the pistillate inflorescences was possible 
the growing plants were numbered and classified with respect to the 
character of the tassel. The* classification was made on the general 
appearance of the tassel, and the following classes were recognized: 
Normal, half tunicate, full tunicate, ramosa , and tunicata-ramosa, the 
last class comprising those plants in which both tunicata and ramosa 
characters could be recognized, and frequently with more or less tend¬ 
ency to “cauliflower/ 1 
There was no occasion for doubt regarding the plants referred to the 
normal class. The presence of the tunicata character was also unmis¬ 
takable, but the distinction between half and full tunicate was not 
always easy to make. In the whole field there were three plants re¬ 
corded as intermediate between half and full tunicate. The plants 
referred to ramosa formed a fairly distinct class, though it was evident 
that in many of the plants the tassels were more dense with longer 
glumes and more nearly pendent than was normal to pure ramosa , 
suggesting the presence of tunicata characters. There was, thus, some 
intergradation between the ramosa plants and those classed as tunicata- 
ramosa . This uncertainty was dispelled when the ears were later exam¬ 
ined, the ramosa and tunicata-ramosa classes proving to be completely 
discontinuous. 
GAMETIC COMPOSITION 
The numbers in which the various classes of plants occur are capable 
of explanation by the assumption of a comparatively simple gametic 
composition. The terminology here used is to assign a letter to the 
dominant member of each allelomorph and the same letter, primed, to 
the recessive member. To those who are accustomed to the presence 
and absence method of notation it will only be necessary to look upon 
the primed letters as the absence of the factor, usually designated by a 
lower-case letter. The custom followed by many workers of assigning 
the unmodified letter to the factor as it exists in the wild or unmutated 
form is impracticable in agricultural plants. Since we have not this 
base line, the unmodified letter is assigned to the dominant member. 
On this basis, beginning with the dominant form, full-tunicate plants 
may be assigned the gametic composition TTRR , T representing the 
tunicate factor and R the dominant allelomorph to the ramosa factor. 
Ramosa , the other parent, would then be T'T'R'R '. Ordinary maize with 
