The Hexacanth Embryo of a Dilepipid Tapeworm. II. The Epidermal Glands and Post-Maturation Changes

Abstract

In Dilepis undula, the epidermal glands, located in the cortex of the oncosphere, are restricted to the region behind the hooks. Gland primordia are present in embryos before hook blades are completed. The large granules characteristic of these cells stain prominently with cytoplasmic stains. Their acidophilic and metachro-matic properties increase in the post-maturation condition. Gland nuclei become enclosed by a dense region of ribonucleic acid. Post-maturation changes are shown by epidermal glands, nuclei, hook position, and parenchyma. There are 2 kinds of embryonic secreting areas in oncospheres (1) Epidermal glands as in Dilepis and Hymenolepis; (2) Mesenchymal glands, as in Taenia and Mesocestoides, composed of several RNA-rich cells.