500 



GLOSSARY 



outer wall of the firm capsule containing- the 

 essential organs of hearing-. 

 Fertilization, the fusion of two nuclear masses, 

 commonly derived from different individuals. 

 Fetlock, in limbs of Horse, &c. : (i) the 

 knuckle-joint of the single digit ; (2) the tuft 

 of hair attached to this joint. 

 Fibula (L. for bodkin), the bone of the lower 



leg- which is on the little-toe side. 

 Fibulare, a proximal element of the tarsus, 



situated on the side next the little toe. 

 Filoplume, a small and imperfect feather, of 



downy texture. 



Finger-and-Toe. See Anbury. 

 Fin-rays, in Fishes, skeletal rods which sup- 

 port the fins. 



Fins, in various aquatic animals, flat expan- 

 sions of the body used in swimming-. 

 Fission (L. findo, fissum, to split), vegetative 

 propagation by splitting- of the parent body. 

 Flagellum, pi. -a (L. for whip-lash), an elon- 

 gated thread of protoplasm, capable of 

 executing lashing movements. A single cell 

 bears but one or a few. See Cilium. 

 Flexor, applied to muscles which bend or flex 



a limb, or region of the body. 

 Fluke, in Cetaceans, one of. the tail-lobes. 

 Fly-sickness, a fatal disease of horses, &c., 



set up by the attacks of the tsetse-fly. 

 Food-vacuole, in Animalcules, a food-contain- 

 ing space within the body. 



Food-yolk, nutritive material stored up in (or 

 outside) the egg-cell, for use during develop- 

 ment. 



Foot: (i) in broad sense, the extremity of any 

 limb used for locomotion ; (2) more strictly, 

 the extremity of a hind-limb in Vertebrates ; 

 (3) an unpaired muscular projection from the 

 under side of a Mollusc, used in locomotion. 

 Foot-stump. See Parapod. 

 Foramen, pi. -ina (L. for hole), a hole through 

 which (usually) a nerve or blood-vessel 

 passes. Foramen magnum, the large open- 

 ing in the back of the brain-case, where brain 

 and spinal cord are continuous. 

 Foramina repugnatoria, in Millipedes, small 

 pores on the sides of the body, by which the 

 stink-glands open. 



Fore-gut, the front part of the digestive tube, 

 developed as an inpushing from the exterior. 

 Fossils (L. fossilis, dug out), the remains of 

 organisms, or proofs of their existence, 

 which have been naturally imbedded in 

 rocks. 



Frenulum (L. dim. of frenum, a bridle), in 

 Moths, one or more bristles projecting from 

 the front of the hind-wing, and attaching 

 this to the fore-wing by interlocking with 

 the Retinaculum (which see). 

 Funicle (L. funicuhis, a cord), in Moss-Po- 

 lypes, a fibrous band connecting the stomach 

 with the body-wall. 



Funnel, a muscular tube through which Cuttle- 

 fishes, &c., eject water from the gill-cavity, 

 and are enabled to swim. 



Furcula (L. for a prop), the " merry -thought" 

 of a Bird, consisting of the two collar-bones 

 united together. 



Galea (L. for a helmet), in Insects, the outer 



branch of the second or third jaw. 

 Gall: (i) bile; (2) an abnormal external growth 



resulting from the attack of a parasite. 

 Gall-bladder, a membranous bag in which 



bile is temporarily stored. 

 Ganglion, pi. ganglia (Gk. for a small tumour), 



an aggregation of nerve-cells. 

 Gangli<fn-cell. See Nerve-cell. 



Ganoid (Gk. ganos, brilliancy; etdos, appear- 

 ance), applied to the regularly arranged 

 bony plates (ganoid scales) covering the 

 bodies of some Fishes. 



Gapes, in Birds, a disease due to the presence 

 of parasitic worms (Syngamus trachealis] in 

 the air-passages. 



Gastric glands, minute tubes imbedded in the 

 lining of the stomach, and secreting gastric 

 juice. 



Gastric juice, a digestive fluid secreted or 

 elaborated by the gastric glands. It acts 

 on albuminoids, converting them into soluble 

 diffusible peptones. 



Gastric mill, in Crustaceans, a chewing 

 apparatus with which the stomach is pro- 

 vided. 



Gastrula (L. dim. from gaster, a stomach), a 

 double -layered embryo possessing mouth 

 and digestive cavity (archenteron). 



Gemmation (L. gemma, a bud), production of 

 new individuals by budding. 



General aggressive resemblance, applied to 

 predaceous forms which harmonize in 

 appearance with their surroundings, and 

 are thus rendered inconspicuous. 



Genus, pi. genera (L. for a race or family), 

 a classificatory group including one or more 

 species. 



Germinal disc, that part of the egg which, 

 e.g. in a Bird, develops into the embryo. 



Germinal variation, variation of germ-cells 

 (ova and sperms). 



Germ Plasma, that part of the nucleus of a 

 germ-cell concerned (according to Weis- 

 mann) with heredity. 



Gill arches and clefts, in Fishes, &c., those 

 visceral arches and clefts (which see) related 

 to the gills. 



Gill-cover, or Operculum, (pi. -a), in many 

 Fishes, &c., a flap which covers the gill-slits. 



Gill-rakers, in some Fishes, filaments project- 

 ing from the edges of the inner openings of 

 the gill-pouches, and serving as a straining- 

 apparatus. 



Gizzard, in various animals, a thick -walled 

 part of the digestive tube in which food is 

 broken up. 



Glenoid cavity (Gk. glene, a shallow socket), 

 the socket into which the bone of the upper 

 arm fits. 



