TRICHOCEPHALUS. 



[ 779 ] 



TRICHODACTYLUS. 



abdominal cavity. Luschka regards this 

 as the male organ, and the dark-looking 

 body as the testis ; but no spermatozoa have 

 been detected. 



Some of the cysts and worms are found 

 in a state of fatty degeneration, with gra- 

 nules or globules of fat, and calcareous 

 matter. 



Trichina is admitted to the human body 

 with the food. It exists in two different 

 conditions. In one it is sexually immature: 

 and it then inhabits the muscles, of the pig 

 or rabbit for instance, in vast numbers, each 

 worm being coiled up in its capsule or cyst. 

 It is incapable of further development under 

 these circumstances. But if a portion of 

 the muscle be eaten by a warm-blooded 

 vertebrate animal and so introduced into 

 the alimentary canal, the immediate de- 

 velopment of young Tnctina is the result. 

 The immature worms escape from the cysts, 

 grow larger, develop sexual organs, and 

 produce viviparously a numerous progeny. 

 The young TrickbuB thus produced perfo- 

 rate the walls of the digestive system, and 

 after working into the muscles become 

 encysted. 



It is important that every one should know 

 the appearance of meat infected with this 

 worm, as it produces serious disease, and 

 even death. It is stated that 8 per cent, 

 of the slaughtered American pigs contain 

 Trichina. 



Three or four other doubtful species have 

 been described. 



BIBL. Owen, Zool. Tr. i. 315 ; Luschka, 

 Siebold # Roll. Zeitschr. iii. 69; Bristowe 

 andRainey, Tr.PatA.Soc.v.274; Du].Ifel- 

 mint/ies, 293 ; Herbst, Ann. Sc. Nat. 3. xvii.; 

 Kobelt, Valentin's Rep. 1841 ; Leuckart,Pr. ; 

 Bakody, Sieb. fy Koll. Zeit. 1872, 422 ; Vir- 

 chow/Qw. Mic. Jn. 1861, 44; Cobbold, 

 Parasit. 149 ; and the BIBL. of ENTOZOA. 



TRICHOCEPH'ALUSjGoeze. A genus 

 of Nematoid Entozoa. 



Char. Body elongate, composed of two 

 parts, the anterior longer and capillary, the 

 posterior becoming suddenly broader ; spi- 

 culum of male simple, long, and surrounded 

 by a sheath. 



The species occur in the large intestine, 

 principally the caecum of man and the mam- 

 malia. 



T. fh'spar (PI. 21. fig. 19, the male: fig. 

 21, the female). 



Anterior portion of the body, spiral in the 

 male, containing the oesophagus only, or 

 the first moniliform portion of the intes*itine ; 



posterior portion containing the rest of the 

 intestine and the reproductive organs. Anus 

 situated at the posterior obtuse end of the 

 body. Integument transversely striated, 

 and with a longitudinal band studded with 

 papillae (PI. 21. fig. 20). Oviduct termi- 

 nating at the point of junction of the two 

 portions of the body ; ova (fig. 21 a) oblong, 

 covered by a resistant shell, with a short 

 neck at each end. 



BIBL. That of ENTOZOA. 



TRICHOCO'LEA, Nees. A genus of 

 Jungermannieae (Hepaticae), containing one 

 British species, T. (Jung.} tomentella, grow- 

 ing in moist places in the west and north of 

 England, Scotland, and Ireland. It is re- 

 markable for the character of the leaves, 

 which are cut up into compound capillary 

 segments, giving the plant a spongy texture. 

 Colour pale. 



BIBL. Hook. Brit. Fl. ii. pt. 1. 127 ; Br. 

 Jung. pi. 36 ; Ekart, Synops. Jung. pi. 6. 

 fig. 49 ; Endlicher, Gen. Plant. Supp. 1. no. 

 472, 15. 



TRICHO'DA, Miill. A genus ofHolotri- 

 chous Infusoria. 



Char. Free, ovate or club-shaped, trun- 

 cate in front ; mouth anterior, with a lip or 

 vibratile membrane; cilia very fine, oral 

 larger. 



T. pur a, oblong attenuate in front ; in 

 putrid infusions, of hay &c. ; length 1-720". 



T. carnium, in putrid-flesh water. 



T. pyrum, in pond water. 



T. angulata, Duj. (PI. 32. fig. 7), oblong, 

 obliquely and irregularly folded or angular, 

 with one or more superficial vacuoles ; fresh- 

 water; length 1-700". 



BIBL. Ehr. Inf. 306; Dui. Inf. 395. 



TRICHODACTYLUS, Dufour. A ge- 

 nus of Acarea (Acarina). 



Rostrum short, with minute setae j fourth 

 pair of legs longer than the rest, without 

 claws, but terminated by a very long seta. 



T. Osmice. Glabrous, pale red, with two 

 marginal setae on each side ; legs and pos- 

 terior part of the body darker ; length 1-50' '. 



T. Osmice, on an Ostnia ; T. Xylocopa, on 

 Xylocope ; another species in hornets' nests. 



Murray unites the three genera, Hypo- 

 pus, Trichodactylus, and Ifomopus into a 

 family, Hypopidae ; while Me*gnin declares 

 them to be the nymphse of Acarea. 



In all, the hinder pair of legs is rudimen- 

 tary, hairs replacing claws. 



BIBL. Dufour, Ann. Sc. Nat. 2. xi. 276 ; 

 Gervais, Walckenaer's Aptires, iii. 266: 

 Murray, EC. Ent.26l j Megnin, Paras. 146. 



