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usual proter and opisthe . Fission : cell division; asexual reproduction; the sole mode of reproduction (nuclear mitosis and exclud- ing meiosis) in ciliates; many kinds or types – iso - or anisotomy ( filial products of equal or unequal size), palintomy, strobilation , and budding ; a cystic stage is sometimes regularly involved; in the usual binary fission, the anterior filial product is called the proter and the posterior filial product, the opisthe ; see also Homothetogenic Fission , Interkinetal , Perkinetal , and Symmetrogenic Fission . Fixation Organelle : see Holdfast Organelle . Flange : literally, “a projecting rim”, used variously in ciliatology (e.g., an ectoplasmic flange underlies part of the paroral in the hymenostome Glaucoma ). Food Vacuole : intracellular vacuoles formed (usu- ally) at the distal end of the cytopharynx and containing food materials in either a particulate or dissolved state; the food vacuolar membrane, supplied in the region of the cytopharynx , may originate in discoidal vesicles or packets delivered with the aid of certain microtubules in the vicinity; digestion takes place within the food vacuoles after fusion of acidosomes and lysosomes ; solid egesta are often discharged through a cytoproct ; also called phagosomes, phagocytic (“cell engulfing”) vacuoles or gastrioles. Forma : see mention under Variety . Fragmon : see Kinetofragment . Frange : band of perioral ciliature characteristic of certain nassophoreans ; varying in composition from an extensive line of specialized ciliature winding around much of the anterior end of the organism to a short linear group of as few as three pseudo membranelles or pavés adjacent to the cytostome proper; sometimes called an adoral cili- ary fringe, but more often the hypostomial frange (ACF, Fig. 2.5Ae; HF, Fig. 2.3i). Fringe : on occasion, used alone or in other combi- nations, with different meanings; sometimes incor- rectly used when frange is meant; see Locomotor Fringe . Fusiform Trichocyst : see Trichocyst . G Gamma Membranoid : see Membranoid . Gametic Nucleus : the haploid nucleus derived by meiosis from the diploid micronucleus prior to conjugation ; meiosis may be followed by mitosis to produce the gametic nuclei. Gamone : soluble substances active in inducing conjugation (e.g., see Blepharmone ). Gamont : members of a conjugating pair (iso- or anisogamonts, equal or unequal in size, with the latter kind including micro- and macrogamonts or more commonly micro - and macroconjugants ); usage of this terminology is not widespread in cili- atology; see Conjugation . Gastriole : see Food Vacuole . Gemmation : see Budding . Generative Nucleus : see Micronucleus . Germinal Field : line of non-ciliferous kinetosomes associated with the terminal portion of the infracili- ary base of the paroral or haplokinety of peritrichs ; serves as an anlage in stomatogenesis in peritrichs , and may be homologous with the scutico-vestige of scuticociliates (GF, Fig. 2.6Ac). Germinal Kinety : see Germinal Field . Germinal Row : see Germinal Field . Glandule, Secretory : see Ampulla, Secretory . Golgi Apparatus (pl. Apparati ): intracytoplasmic membranous structure consisting of flattened sac- cules (cisternae), often stacked in parallel arrays, and vesicles ; involved in elaboration or storage of secretory products, such as lysosomes and extru- somes ; the Golgi apparatus is not prominent in ciliates, in contrast to the condition in many other protozoa; often called a dictyosome. Golgi Body : see Golgi Apparatus . Grain Convention : see Numbering Conventions . Gullet : non-preferred term used for the buccal cav- ity of ciliates, such as Paramecium . Gymnostome : literally meaning “naked mouth”, and not really appropriate since ciliates with a cytostome have some kind of oral ciliature, the suctorians being a notable exception. Glossary 31 H Haploid : N set of chromosomes; in ciliate life cycles, haploidy is characteristic of the meiotically- reduced gametic nuclei. Haplokinety (pl. Haplokineties ): once-popular term for the infraciliary base of a generalized paroral , especially in ciliates belonging to the class Oligohymenophorea ; typically a double row of kinetosomes (paired tangentially as stichodyads ), joined in a zigzag pattern, generally with only the outermost kinetosomes ciliferous ; also used to mean the entire paroral , the ciliated portion plus its infraciliary base; in scuticociliates , the haplokinety or zeta membranoid has been described as com- prised of one, two, or three kinetosomal segments (see remarks under Membranoid ), depending on the species under consideration (Hk, Figs. 2.6Cc, 2.7a, 2.7b, 2.7e, 2.7i). Haptocyst : minute extrusome in the suctorial tentacles of suctorians ; presumed to contain lytic enzymes useful in the capture of prey organisms; sometimes still referred to as a microtoxicyst, a missile-like body, or a phialocyst (Fig. 2.9Cd). Haptotrichocyst : rod-shaped extrusome of rhyn- chodid phyllopharyngeans ; synonym for acmocyst . Head : generalized term, variously used in ciliatol- ogy, but usually in a nonspecific way. Heterokaryotic : possessing more than one kind of nucleus; characteristic of the great majority of ciliates, with their micro - and macronucleus ; see Nuclear Dualism (Fig. 2.12). Heteromembranelle : specialized term for each of the several to many adoral polykinetids of the clevelandellid armophoreans ; the infraciliary bases of the anterior or third row of kinetosomes are joined to the posterior row by a different (hence “hetero”) set of interkinetosomal connectives; see Paramembranelle . Heteromerous Macronucleus (pl. Macronuclei ): nucleus partitioned into karyomeres ( orthomere and paramere ) with strikingly different DNA and RNA contents, and therefore, with differential staining capacities; found especially in cyrto- phorian and chonotrich phyllopharyngeans ; see also Homomerous Macronucleus (Fig. 2.12r, 2.12bb). Heterotrophic : requiring organic molecules, typically derived from other organisms, to provide nutrients; see Autotrophic and Mixotrophic . Histophagous : literally “tissue-eating”; the feed- ing habit of ciliates living on or in the usually unhealthy (i.e., wounded, moribund, or decaying) bodies of aquatic or edaphic metazoa, including vertebrates (generally larval forms), as well as many kinds of invertebrates of all sizes; blood is one of the preferred tissues for certain ciliates; examples of histophagous forms include species of the hymenostomes Ophryoglena and Tetrahymena and such scuticociliates as Anophryoides , Mesanophrys , and Porpostoma ; often misspelled as “ histiophagous ”. Holdfast Organelle : any structure by which a ciliate can affix or attach, temporarily or permanently, to a living or inanimate substratum (e.g., by use of cilia, hooks, uncini, crochets, tails, loricae, mucous filaments, spines, stalks, suckers, tentacles, and the like); in the usual, more restricted sense, a special- ized organelle, such as stalks of various kinds, the adhesive disc of mobiline peritrichs , the sucker of some astomes or clevelandellid armophoreans , or the localized thigmotactic ciliature of many thigmotrichine scuticociliates ; see Attachment Organelle (Fig. 2.9B). Holotelokinetal : telokinetal stomatogenesis in which the oral anlage is derived by proliferation of kinetofragments from all somatic kineties ; found in haptorians (Fig. 2.11Da). Holotrichous : having somatic cilia evenly distrib- uted over the body surface; see Oligotrichous . Holotype : the individual organism to which is attached the species-group name; often with cili- ates, it is accompanied on a type slide by a number of other individuals,