132 GacER: GLANDS IN THE EMBRYO OF ZEA 
fourth. The diagram (FIGURE 1), shows the location of these 
structures in the scutellum, while they are shown in detail in the 
photomicrographs, FIGURES 2 and 3. Two of them, as may be 
seen in the diagram, are of practically uniform diameter through- 
out, while the other and larger one is enlarged at the end. 
Describing the scutellum of the corn in 1902, Torrey” says : 
« At the region of the tip this secretory epithelial layer dips down 
at frequent intervals into the scutellum. The convolutions so pro- 
duced secure a larger surface of secretion where there is greatest 
need for the enzyme; for the endosperm is thickest at this point 
and in front of the embryo.”’ Whether the structures seen by 
Torrey were the same as those described above is not entirely 
clear from his description, but his figure (/ 7) indicates that they 
were at least very similar. If so, their location is not restricted ‘‘ to 
the region of the tip” of the scutellum, as is clearly shown in 
Fic. 1. Diagram of cross-section of grain of Zea Mays. ¢, combined coats of 
fruit and seed; ¢, endosperm region; s, scutellum; ge, glardular epithelium; 4%, 
tubular glands; xg, gland slightly racemose. . 
FIGURE I herewith. Thus their distribution does not seem to be 
correlated with the thickness of the endosperm. 
What is their significance? The variety of the corn is the 
“ Hickory King,” of J. M. Thorburn & Co., and the grains are 
of uniformly large area, though relatively flat and thin. Because 
of these facts it may be suggested, not unreasonably, that this in- 
vagination of the epithelium is merely an expression of vigorous, 
rapid growth, without corresponding opportunity for expansion. 
An analogy is found in the uneven, crinkled surface of foliage- 
leaves in many plants, due to the fact that one epithelium has 
grown more rapidly than the other. The wrinkling is a ‘‘ mechan- 
