Penetration glands, oncosphere

The process of hatching in the Cyclophyllidea, which results in the release of the oncosphere, has been discussed in Chapter 7. The basic structure of a mature oncosphere (Fig. 8.16), which will not be discussed in detail here, does not vary substantially between species. It is composed essentially of (a) a thin covering epithelium with cytoplasmic extensions, (b) an additional complex system of muscles operating the three pairs of hooks, (c) a pair of large penetration glands, (d) a small core of germinative cells from which the next larval stage develops and (e) a primitive nervous system. 

Hymenolepis nana the fine structure of the penetration gland and nerve cells within the oncosphere. Parasitology, 82 445-58. 

Penetration glands of oncospheres of Hymenolepis diminuta (Cestoda). Histochemical studies. Bulletin de I Academie Polonaise des Sciences, Class II, 25 619-22. 

---