释义 |
procercoid, n. (and a.) Zool.|prəʊˈsɜːkɔɪd| [ad. F. procercoïde (F. Rosen 1918, in Bull. Soc. Neuchateloise des Sci. Nat. XLII. 43), f. Gr. κέρκος tail: see pro-2 1, -oid.] The earliest parasitic form of the larval stage of certain tapeworms, in which the body is solid and has begun to develop a scolex but retains the posterior hooks found in the preceding embryonic stage. Also attrib. or as adj.
1918Jrnl. Amer. Vet. Med. Assoc. LIII. 359 The procercoid loses its hooks and the caudal appendix, if these have not already been lost in the copepod. 1927Jrnl. Parasitol. XIV. 108 This larva resembled very closely the procercoid of D[iphyllobothrium] latum as figured by Janicki and Rosen. 1935Borradaile & Potts Invertebrata (ed. 2) vi. 229 The larva [in Tetrarhynchidea] which may be of either the procercoid or cysticercoid type occurs in marine invertebrates of many kinds, fish and occasionally reptiles. 1942D. L. Belding Textbk. Clin. Parasitol. xxv. 407 When the injected copepod is ingested by a suitable species of fresh-water fish, the procercoid larva penetrates the intestinal wall in a few days and enters the muscles, viscera and connective tissues. 1962,1973[see plerocercoid n.]. 1987Oxf. Textbk. Med. (ed. 2) I. v. 570/2 The procercoid larva or sparganum ingested by a human actively penetrates the intestinal wall to reach the peritoneal cavity, whence it begins to migrate systemically. |