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

Chemical Biology of Secretions of Larval Helminths*

“…Cyclophyllidean oncospheres may be enclosed by several envelopes: the outer, a vitelline shell originating from the parent tapeworm; next within, a rigid inner capsule-either a retained embryonic epidermis or a well-developed embryophore which is formed from epidermal cells of the oncosphere; then a colloidal or albuminous region between oncosphere and shell. A thin inner membrane may or may not be draped over the hooks (Ogren, 1959).…”

“…Membranes within the outer shell capsule develop from oncosphere cells, either by cellular alteration or by cellular secretion (Ogren, 1955(Ogren, , 1956(Ogren, , 1957(Ogren, , 1958(Ogren, , 1959(Ogren, , 1961. At least two types of embryonic secreting areas have been recognized: ( 1 ) epidermal gland cells in such genera as Dilepis and Oochoristica (Ogren 1959); ( 2 ) mesenchymal or plastin cells in Taenia and Mesocestoides (Silverman and Maneely, 1955;Ogren, 1959).…”

“…They will be referred to later. The need for detailed study of this phase of host oestode relationships, emphasized by Ogren (1957Ogren ( , 1959, should be obvious from the diverse developmental patterns encountered in the organisms which have been investigated.…”

Life history of Marsipometra hastata and the biology of its host, Polyodon spathula

“…Preparations with Delafield's hematoxylin or Heidenhain's iron hematoxy lin and counterstained with eosin have shed little light on the nature of these cells. Ogren (1959) described prominent epidermal glands "behind the hooks" in onchospheres of Dilepis undula (Cyclopbyllidea ). Vogel (1929) Finally, experiments were conducted in which the coracidia were fed to a variety of invertebrates in the hope of obtaining subsequent develop mental stages.…”