FILARIA. 



[ 324 ] 



FISSIDENTE/E. 



cells of most of the Confer void Algae, to 

 the mycelium (flocci) of Fungi, and to the 

 medullary layer of the lichens. Many 

 other instances will suggest themselves to 

 the microscopist. 



FILA'RIA, Miill. A genus of Entozoa, 

 of the order Nematoidea. 



Char. Body filiform, very long, nearly 

 uniform ; head not distinct from the body ; 

 mouth round, or triangular, naked or with 

 papillae ; white, yellowish, or red, from 48 

 to 100 times as long as broad; oesophagus 

 short, tubular, narrower than the intestine ; 

 anus terminal, or nearly so ; spicula two, 

 of unequal size, more or less twisted ; 

 vulva situated very near the anterior extre- 

 mity. 



Several species, many of which have been 

 imperfectly examined. They are most 

 commonly found in the abdominal cavity 

 and between the peritoneal folds of mam- 

 malia and birds, in the blood and the air- 

 cells of the latter, sometimes in the subcu- 

 taneous cellular tissue. Species are also 

 met with in reptiles, fishes, and insects. 



F. medinensis. The hair- or Guinea- worm. 

 Common in the intertropical regions of the 

 old world. Length 6 to 10" ; breadth 1-20 

 to 1-10". F. bronchialis occurs in the human 

 bronchi; F. lachrymalis in the lachrymal 

 gland; F. oculi (papillosa) in the globe of 

 the eye, or beneath the conj unctiva ; F. 

 immitis in the heart of the dog ; F. rhyti- 

 pleurites in the cockroach, &c. 



F. sanguinis is capillary, uniform, with- 

 out papillae, the neck narrowed, the tail of 

 female simple, bluntly pointed, the vulva 

 close to the head, and the anus near the tip 

 of the tail ; length of adult 3", of embryos 

 rsir-TV". It is found in the immature 

 form in human blood and urine, in chyluria 

 and endemic haematuria. The adult form 

 occurs in the subcutaneous connective tissue 

 of the scrotum, &c. 



Two species occur in fresh water, under 

 the leaves of aquatic plants : 



F. aquatilis. Fern, white, constricted 

 behind the spherical head ; tegument not 

 striated; oesophagus capillary, very long, 

 sinuous ; tail gradually narrowed to a 

 curved point ; vulva anterior to the middle 

 of the body ; length 3-10 to 4-10"; breadth 

 1-250". 



F. lacustris. Fern, reddish-white, slightly 

 narrowed in front, but without a constric- 

 tion ; mouth very small, lateral, and oblique; 

 oesophagus filiform, very long, nodose at its 

 origin j tail conical, obtuse, terminating 



obliquely in a very small point ; tegument 

 not striated ; vulva behind the middle ; 

 length 1-2" ; breadth 1-140". 



BIBL. Dujardin, Helminth. 42 ; Diesing, 

 Helminth, ii. 263 ; Kiichenmeister, Para- 

 siten, 304; Lewis, San. Comm. Sth Hep., 

 Calcutta, 1872; Leuckart, Parasit. 1879, 

 65 (fig.); Gruby and Delafond, Compt. rc/ifl. 

 xlvi. 1217 ; Leidy and Welch, Mn. Mic. Jn. 

 1873, 157; Ann. N. H. 1878, ii. 199; 

 Cobbold, Parasites, 1879 {most complete 

 literature). 



FILELLUM, Hincks. A genus of ma- 

 rine Hydroid Polypi, fam. Lafoeidae, 



1 species: F. serpew, common on the 

 larger Sertulariidae, especially S. abietina. 



BIBL. Hincks, Brit. Zooph. p. 214. 



FIR. See PINUS, CONIFERS, and 

 WOOD. 



FISCH'ERA, Schwabe. A genus of 

 Oscillatoriaceae (Confer void Algae). 



Char. Filaments irregularly branched, 

 composed of uniserial cells, with interstitial 

 subglobose cell; surrounded by mucus, 

 forming an amorphous gelatinous stratum. 



F. thermalis. On the walls of warm 

 springs (Rabenhorst, Fl. Alg. ii. 285). 



FISSIUEN'TE^E. A family of opercu- 

 late Acrocarpous (sometimes cladocarpous) 

 Mosses, of gregarious or caespitose habit, 

 with simple or much-branched stems. The 

 leaves are amplexicaul (fig. 242), composed 

 of minute parenchymatous cells, closely are- 

 Fig. 241. Fig. 242. Fig. 243. 



Fissidens bryoides. 



Fig. 241. A plant of F. bryoides. Magn. 5 diams. 

 Figs. 242 & 243. Leaves detached. More magnified 

 to show the appendage. 



