The tergal regions of the mesothorax and of the metathorax are hidden under the pronotum and the elytra when the latter are closed, except that the mesothoracic scutellum is of ten visible - a small triangular or semicircular plate between the bases of the elytra (fig.
R and 2, V.) in Hemiptera is large and free, and the mesothoracic scutellum is usually extensive.
The scutellum meanwhile feeds the developing embryo from the endosperm.
The dorsal area of the mesothorax, and also of the metathorax, may be made up of a series of sclerites arranged one behind the other - prescutum, scutum, scutellum and post-scutellum (fig.
Especially in relation to the origin of the vascular bundles which supply them, favours the view that the scutellum and pileole are highly differentiated parts of a single cotyledon,and this view is in accord with a comparative study of the seedling of grasses and of other monocotyledons.