The cuticle contrasts strongly in its nature with the hypodermis it protects.
In such leaves, there are a well-marked cuticle, a thick epidermis, a thick hypodermis at least on the upper side of the leaf, well-developed palisade tissue, and a poorly developed system of air-spaces.
The body is covered by a cuticle which is sculptured and the various markings are of systematic importance: it is secreted by a hypodermis which also includes nerve-cells and some gland-cells.
The adult caterpillar may be described as a creature the hypodermis of which is studded with Adapted from Koerschelt and buds that expand and form the butterHerder, and Lowne.
The hypodermis is composed of parts of two different kinds, viz.
The black represents the cuticular product of the epidermal cells of the ocular area, taking the form either of))...,r,, f lens, cl, of crystalline body, cry, or of rhabdom, rhab; hy, hypodermis or epidermal cells; corn', laterallyplaced cells in the simpler stage, A, which like the nerve-end cells, vit' and ret', are corneagens or lens-producing; corn, specialized corneagen or lens-producing cells; vie, potential vitrella cells with cry', potential crystalline body now indistinguishable from retinula cells and rhabdomeres; vit, vitrella cell with cry, its contained cuticular product, the crystalline cone or body; ret', rhab', retinula cells and rhabdom of scorpion undifferentiated from adjacent cells, vit'; ret, retinula cell; rhab, rhabdom; nf, optic nerve-fibres.
By histolysis certain parts of the hypodermis are destroyed, while other portions of it develop into the new structures.
The hypodermis is the immediate agent in effecting the external changes.