Filiform: thread-like. 



Fission: division of a cell by splitting to form two, not necessarily equal, parts; 



cell division without mitosis. 

 Flaccid: soft, drooping, not rigid. 



Flagellum: a stout, whip-like organ of locomotion which arises within the cell. 

 Flagelliform: whip-shaped. 



Flange: a longitudinal ridge extending vertically from a cell wall. 

 Flexuous: pliable; not firm or rigid. 

 Floccose, Flocculent: cottony, or wooly; matted. 

 Floridean starch: a carbohydrate food reserve in the Rhodophyceae. 

 Foliaceous, Foliose: like a leaf. 

 Frond: a flat, leaf-Hke plant; a foUaceous thallus. 

 Frustule: the shell of diatoms. 

 Fusiform: an elongate figvue broadest in the middle and tapering at each end; 



spindle-shaped. 

 Gametangium: a gamete-producing cell; sex organ. 

 Gamete: a sex cell, male or female reproductive cell. 

 Gelatinous envelope: a sheath or investment of mucilage-like substance. 

 Geniculate: with knee-bendings. 



Germling: young plant developed from a spore or zygote. 

 Gibbous: swollen in a regular curve. 

 Girdle: a band or belt, usually median; part of the structure just within the 



wall, and lateral in the cell, which holds the valves of diatoms together. 

 Girdle view: a lateral or side view of a diatom, showing the overlapping of the 



two wall sections. 

 Glaucous: grayish-green; green with a whitish overcast or 'bloom.' 

 Glomerate: in compact clusters. 

 Glomerule: a small compact cluster. 



Glycogen: a white carbohydrate, amorphous, similar to starch; a food reserve. 

 Gonidium: a spore-like, thick- walled reproductive cell (see akinete). 

 Gonimoblasts: short filaments developing from the zygote in certain Rhodo- 

 phyceae which cut off spores ( carpospores ) at their tips. 

 Granulose: furnished with granules. 



Gregarious: growing in clusters or in close associations; not solitary. 

 Gullet: an opening through the membrane at anterior end of flagellates 



( euglenoids ) . 

 Gynandrosporous: in Oedogoniaceae, a condition in which androspores (spores 

 which produce male plants) are developed in the same filament in which 

 oogonia ( female organs ) occvir. 

 Gypsum: granules of calcium sulphate found in the cells of some desmids. 

 Haematochrome: a red pigment apparently functioning as a Ught screen, 



appearing occasionally in green algae, sometimes permanently present. 

 Haploid: containing the half number of chromosomes (nucleus with the 1-n 

 number); referring to a generation in the life history following reductive 

 division. 

 Haplontic: a haploid or 1-n generation; referring to a cell containing the re- 

 duced number of chromosomes. 

 Hapteron ( pi. Haptera ) : an anchoring, finger-like organ at the base of a young 



plant. 

 Heleoplankton: floating organisms in a small, shallow pond. 

 Helotism: a form of symbiosis; two different species in close association 

 ( lichens ) . 



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