GLOSSARY 433 



Carinal canal. In the Equisetinae, one of the canals in the stele of the stem Ij'ing 

 beneath a ridge on the surface. 



Carotin. Any of a group of mainly deep yellow to orange-red pigments found in var- 

 ious plants, eitlier alone or associated with others, particularly chlorophyll; they 

 differ from the xanthophylls in containing only carbon and hydrogen. 



Carotinoid. Any of a group of pigments that includes the carotins and xantliophylls. 



Carpel. The megasporophyll or ovule-bearing organ of seed plants; in angiosperms, 

 forming a simple pistil or part of a compound pistil. 



Carpogonium. In the red algae, the basal portion of the procarp where the egg is 

 formed, or sometimes comprising the entire female sex organ. 



Carpospore. In the red algae, one of a group of nonmotile spores produced either by 

 the zygote directly or budded off from the tips of short filaments arising from the 

 carpogonium after fertilization. 



Cauline. Growing on, or belonging to, a stem. 



Cellulose. A carbohydrate constituting the chief substance in the cell wall of plants. 



Chalaza. The portion of an ovule below where the integuments are united to the 

 nucellus. 



Chalazogamy. Fertilization of an egg by means of a pollen tube entering the ovule 

 through the chalaza. 



Chlamydospore. A thick-walled resting spore produced in certain fungi, particularly 

 the smuts, and representing a transformed vegetative cell. 



Chlorophyll. The green coloring matter of plants, occurring in two associated forms, 

 chlorophyll a and chlorophyll b. 



Chloroplast. A plastid containing chlorophyll. 



Choripetalous. Having separate petals. 



Chromatin. A deeply staining, granular, protoplasmic material occurring in the 

 nucleus of cells. 



Chromosome. One of the organized bodies, of definite number, into which the 

 chromatin of a nucleus resolves itself in connection with mitotic division. 



Cilium. A hair-like protoplasmic process capable of vibratory or lashing movement. 



Circinate. Coiled ; rolled up on the axis with the apex at the center. 



Cleistothecium. A closed ascocarp. 



Coccus. A spherical bacterium. 



Coenocyte. A plant body, as in some algae and fungi, the protoplasm of which is con- 

 tinuous and multinucleate and not divided into separate cells. 



Coleorhiza. In some seed plants, a sheath covering the root tip of an embryo. 



Collateral. Side by side, as the arrangement of xylem and phloem in the vein of a leaf. 



Colony. A group of unicellular plants of the same kind held together by a common 

 investment or stalk. 



Columella. A sterile central portion of the sporangium of certain molds; a sterile cen- 

 tral axis in the capsule of certain liverw^orts and mosses. 



Companion cell. A cell associated with a sieve tube in the phloem of angiosperms and 

 of common origin with it. 



Conceptacle. In certain algae, as in the Fucales, a cavity with an external opening 

 containing reproductive cells. 



Conidiophore. In certain fungi, a specialized hypha that produces conidia by 

 abstriction. 



Conidium. An aerial spore produced by abstriction from the tip of a conidiophore. 



Conjugation. The fusion of two similar gametes. 



Corolla. The petals of a flower, collectively; the inner whorl of perianth parts. 



Corpus. The central growth zone in a stem tip. 



