FILARIA. 



[ 264 ] 



FISSIDENTE^E. 



elongated cellular filaments with thin and 

 collapsing walls. It would include all long 

 vegetable hairs, like those formingthe comaon 

 many seeds (Poplars, Asclepias, Gossypium, 

 &c.), also those forming felty coatings on 

 the epidermis, as in many Composit8e,&c. It is 

 also applicable to the cells of most of the 

 Confervoid Algse, to the mycelium (flocci) of 

 Fungi, and to the medullary layer of the 

 Lichens. Many other instances will suggest 

 themselves to the microscopist. 



FILARIA, Miill. A genus of Entozoa, of 

 the order Ccelelmintha, and family Nema- 

 toidea. 



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 ; oesopha- 

 gus short, tubular, narrower than the in- 

 testine; anus terminal, or nearly so; spi- 

 cula two, of unequal size, more or less twisted; 

 vulva situated very near the anterior extremity. 



Several species, many of which have been 

 but imperfectly examined. They are most 

 commonly found in the abdominal cavity, 

 and between the peritoneal folds of mam- 

 malia and birds, in the air-cells of the latter, 

 sometimes in the subcutaneous cellular tis- 

 sue. 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. lachrymaUs. In the lachrymal gland. 



F. oculi. In the globe of the eye, or be- 

 beneath the conjunctiva. 



Two species occur in fresh water, under 

 the leaves of aquatic plants. 



F. aquatilis. Fern, white, constricted be- 

 hind the spherical head ; tegument not stri- 

 ated ; oesophagus capillary, very long, sinu- 

 ous; 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 constriction; 

 mouth very small, lateral, and oblique ; oeso- 

 phagus filiform, very long, nodose at its 

 origin; 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, Helminthes, p. 42; V. 

 d. Hoeven, Handb. d. Zool p. 179. 



FILICACE.E. See FERNS. 



FIR. See PINUS, CONIFERS, and WOOD. 



FISSIDENTE^E. A family of opercu- 

 late Acrocarpous (sometimes cladocarpous) 

 Mosses, of gregarious or crespitose habit, 

 with simple or much-branched stems. The 

 leaves are amplexicaul (fig. 247), composed 

 of minute parenchymatous cells, closely are- 



Fin-. 245. 



Fig. 251. 



Fig. 246. 



Fig. 248. 



Fig. 247. 



Fissidens bryoides. 



Fig. 245. A plant of F. bryoides. Magn. 7 diams. 



Figs. 246 & 247. Leaves detached. More magnified to 

 show the appendage. 



Figs. 248, 24Q, 250. Sections of 246, at various heights 

 from the base. 



Fig. 251. Fragment of peristome. Magn. 100 diams. 



olated, often very papillose, produced at the 

 back and point into a lamina beyond the 

 leaf (figs. 246 - 250), whence three parts 

 are distinguished in the latter: 1, the 

 true horizontal blade ; 2, the dorsal lamina, 



