Dr. Murai Éva szerk.: Parasitologia Hungarica 13. (Budapest, 1980)

adsorption seemed to depend on the metabolic rate of the parasites. The larvae preincubated in OC-amylase containing medium at a low environmental temperature adsorbed a lesser quantity of enzyme than those preincubated at 38°C. Stimulation and adsorption of mammalian pancreatic oC-amylase by the parasites suggested the operation of a "membrane .digestion" mechanism (UGOLEV, 1968) in the larval stages of L. intestinalis. Earlier studies suggested that the membrane digestion process becomes activated only by adsorption of host amylase to the parasite's surface, but the present studies indicate that intrinsic amylase probably also appears on the surface of the tegument. According to UGOLEV (1965) the intrinsic enzyme is transported to the surface via exocytosis, in vacuoles, and becomes adsorbed to the appropriate surface structures. The residual amylase activity detected by us after removal of the tegument's brush border by the method of OAKS et al. (1977) indicated the presence of the enzyme also in the proximal cytoplasmic locations of the tegumental cells. This accords well with the observations of KWA (1972b) on Spirometra erinacei sparganum larvae, whose tegumental cells were found to contain organelles ("pit organelles" and a "packet of granules") not seen in any other species. KWA has postulated that the granules become secreted on the surface and, after adsorption thereto, collaborate in the membrane digestion mechanism. Granule-like, membrane-bound bodies can in fact be observed on the surface of the tegument. Since L. intestinalis and Spirometra erinacei equally belong to the family Pseudophyllidea, there is reason to believe that similar morpholpgical and physiological processes take place in the tegument of both species. REFERENCES DU BININA, M.N. (1966): Remneci Cestoda Ligulidae fauni SSSR. - Moskva- Leningrad, Izd. Nauka, pp. 259. KWA, B. (1972a): Studies on the sparganum of Spirometra erinacei. II. Proteolytic enzyme(s) in the scolex. - Internat. J. Parasitol. , 2'. 29-33, KWA, B. (1972b): Studies on the sparganum of Spirometra erinacei. III. The fine structure of the tegument in the sparganum scolex. - Internat. J. Parasitol., 2. 34-38. LUMSDEN, R.D. (1975): Surface ultrastructure and cytochemistry of parasitic helminths. Exp. Parasitol., 58. 864-871. PAPPAS, P. W. - READ, C. P. (19 72): Trypsin inactivation by intact Hymenolepis diminuta. J. Parasitol., 58. 864-871. READ, C.P. (1973): Contact digestion in tapeworms. - J. Parasit., 59. 672- 677. READ, C.P. - ROTHMAN, A. - SIMMONS, J.E. (1963): Studies on membrane transport with special reference to host-parasite integration. - Ann. N. Y. Acad. Sei., 113

. 154-205. SMYTH, J.D. (1967): Studies on tapeworm physiology. IX. In vitro cultivation of Echinococcus granulosus from the protoscolex to the strobilate stage. - Parasitol. , 57

. 111-133. SMVTH, J.D. (1972): Changes in the digestive-absorptive surface of cestodes during larvaladult differentiation. - in Functional. Aspects of Parasite Surfaces, Symp. of the British Soc. for Parasitol. , 10_. 41-70. SMYTH, J.D. - MILLER, H.J. - HOWKINS, A.B. (1967): Further analysis of the factors controlling strobilization, differentiation, and maturation of Echinococcus granulosus in vitro. - Exp. Parasitol., 21. 31-41, TAYLOR, R. - THOMAS, J. (1968): Membrane (contact) digestion in the three species of tapeworm Hymenolepis diminuta, Hymenolepis microstoma and Moniesia expansa.Parasitol., 58. 535-546.