D - A histological study was carried out on several strains of native and cultivated corn and of a North-American pop corn. The structure of the latter was identical with that described by Randolph. In corn of the Paraguay river group, as defined above, the following structural elements were the most striking:
The spikelets appear to have a pronounced pedicel.
At the lower base of the pedicel and at its sides a scaly outgrowth of the rachis appears which thus surrounds the alveolus on three sides, and which corresponds to the cover of the kernels in Tripsacum and Euchlaena.
The spikelets of Paraguayan corn which when mature had the kernels half covered by glumes, had at flowering time the same structure as "São Paulo Pod" corn with well developed glumes.
F. G. Brieger and H. C. Cutler