Confluent: growing into one another; soft sheaths which run together or which 



become intermingled. 

 Conidium: a spore cut oflF from the tip of a cell, or from a filament. 

 Connate: pointed; imited for a short distance as in the basal portion of branches. 

 Constricted: pinched in; deeply incised. 

 Contiguous: near-by, adjoined. 



Conjugation: union of gametes from cells or from plants which become joined, 

 the gamet^j moving together in an amoeboid fashion; hterally, a yoking 

 together. 

 Contorted: irregularly twisted. 

 Contractile: able to expand and contract. 

 Contractile vacuole: cavity in the cytoplasm surrovmded by a membrane which 



shows pulsating actions, compressing and expanding. 

 Convolute: rolled together; rolled inward from a margin. 

 Cordate, Cordiform: heart-shaped. 



Coronula: a crown of cells at apex of oogonium in Characeae. 

 Cortex, Corticating: a layer of cells or filaments which invest or grow around 

 a central core (cell or filament), forming an inclosing layer (e.g., some 

 Rhodophyceae, Chara). 

 Corymb (Corymbose): a flat-topped cluster (especially when sequence of 



development is from outside toward the center ) . 

 Costa (Costate): rib (adj., ribbed). 

 Craticular stage: a condition in diatoms in which successively formed cell walls 



nest within one another. 

 Crenate: with a wavy surface or margin. 

 Crenulate: finely crenate; wdth small scallops. 

 Cuspidate: furnished with a tooth. 

 Cruciate: cross-like in arrangement. 

 Cryoplankton, Cryovegetation: plants which live in snow, especially perpetual 



snow banks of alpine situations. 

 Cuneate: wedge-shaped. 

 Cushion-like: said of a thallus composed of a mound of cells, two to many 



layers of cells; parenchymatous. 

 Cylindrical: elongate and round in cross section viith parallel lateral margins. 

 Cyst: a dormant, vegetative reproductive cell, usually with a heavy wall. 

 Cystocarp: a structure that develops around the fertiUzed egg in the Rhodo- 

 phyceae in which spores ( carpospores ) are formed. 

 Cystosome: soft portion of periplast of flagellates in the food-absorbing region. 

 Cytopharynx: a canal extending back from the anterior opening in flagellates; 



narrow part of gullet in euglenoids. 

 Daughter cells. Daughter segments: cells or portions of thallus that are des- 

 cended from the same mother cell or parent plant. 

 Decumbent: growing horizontally but with the segment ascending (c.f. pros- 

 trate). 

 Deliquescent: degenerating; dissolving. 

 Dendroid: tree-like, branching as in a tree. 

 Dentate: toothed; with blunt-pointed projections. 



Depressed- globose: not quite spherical; like a slightly flattened sphere. 

 Diastole: period of expansion in action of contractile vacuole. 

 Diatomaceous earth: grayish-colored silicious deposit of diatom shells. 

 Diatomin: brown pigment found in diatoms. 



Dichotomous, Dichotomy: divided or forked into two parts; forking branches. 

 Dioecious: "two households"; with male and female organs on separate plants. 



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