166 GENERAL BIOLOGY 



chlorophyll. The green coloring matter of plants. 



chloroplast. A chlorophyll body or granule. 



chromatin. The ingredients of the nucleus which stain 

 deeply with certain dyes. 



chromosome. A distinct body formed from the chromatin, 

 and present only at the time of nuclear division. 



cilia. Minute, vibratory, protoplasmic processes on a cell. 



circum-esophageal. About the esophagus. Refers to the 

 nerve connectives joining the ventral cord and cerebral 

 ganglia of invertebrates. 



cleavage. Splitting or division of the egg cell at the be- 

 ginning of development. 



clitellum. A thickened, glandular region of the earthworm 

 which secretes the egg case. 



cloaca. A chamber into which empty the intestine, kidneys, 

 and reproductive organs. 



coccus. A spherical bacterium. 



ccelom. The body cavity; the space between digestive 

 tube and body wall. 



coenosarc. The fleshy stalk or stem of hydroids, uniting the 

 various polyps. 



colony. A group of animals living or growing together, the 

 various individuals being connected. 



commissure. A band of nerves connecting ganglia in in- 

 vertebrates; tracts of nerve fibers within the central 

 nervous system of vertebrates. 



conjugation. A temporary or permanent fusion of cells in 

 reproduction. 



contractile vacuole. A pulsating vacuole in protozoa hav- 

 ing an excretory function. 



corpuscle. A cell of an animal body floating in a fluid or 

 separated by an intercellular matrix. 



