60 
Zea * amyleasaccharata. The 
Starchy Sweet Corns. This * species 
is founded upon three varieties 
found in the San Padro village col- od 
lection. The external appearance is that of the Zea * sac- 
charata, but the horny matter in our specimens more trans- 
lucent. Its distinguishing character, however, is in the in- 
ternal arrangement of the kernel, the lower portion being: 
starchy, the upper horny and translucent. 
Within these * species, certain variations pursue a parallel 
course, and these we at present distinguish under letters of 
the alphabet, as below, and term Races: 

A. Kernel broader than deep. 
B. Kernel as broad as deep. 
©. Kernel mnch deeper than broad. 
In general, but with some exceptions, the corns of Race 
A have in the main a cylindrical cob, and a medium stalk, 
the kernels not rounding over but, and well marked tend- 
ency to swell at the but through added kernels or rows. 
They are usually 8-rowed. Here, however, we must prov- 
isionally class certain corns with small ear stalk, and fusi- 
form ear. 
In Race B we have in the main a slightly tapering cob, 
a large ear stalk, a tendency to swell at the but through 
added kernels or rows, the kernels not rounding over the 
but, usually 12- rowed varieties. We must provisionally 
class here, also, a few fusiform shaped cobs with small ear 
stalks. 
In Race C we find usually a small, often very small ear- 
stalk, a strongly tapering or fusiform or cone-form ear, 
kernels rounding over the but, and the varieties many 
rowed. 
With a less material for study, these races would show a 
well marked separation, as illustrated in my classificatory 
attempt of 1884, founded upon shape of ear; but these later: 
collections of Mexican Indian products indicate that the 
form of the kernel has a double set of corelations with the: 
cob and the ear. 
A second group of uniformities with parallel occurrence: 
within the Races, and the starred species may be called 
Tribes, the distinction being founded upon the shape of the: 
ear, as follows: 
Tribe I. The ear cylindrical, or mainly so, from but. 
Il. The ear tapering, from but. 
II. The ear tapering both ways from a point below the but, ovak 
or fusiform or cone form; often the appearance expressed by the description: 
as rounding over the but. 

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