GLOSSARY 563 



Cerebrum (ser'-e-brum), a division of the brain of chordates. 

 Cervical (siir'-vi-kal), pertaining to the neck. 



Cheliped (kel'-i-ped), the large pincher of the crayfish, lobsters, and crabs. 

 Chitin (ki'-tin), a horny substance forming the outer covering of many Arthro- 

 poda; also forms internal structures in some Arthropoda and other forms 



of life. 

 Chloragogue (klo'-ra-g6g), refers to the cells on the outside of the intestine of 



the earthworm. 

 Chlorophyll (klo'-ro-fil), the green coloring matter in plants; the material that 



manufactures food in plant cells. 

 Chorion (ko'-ri-on), one of the embryonic membranes of higher vertebrates. 

 Choroid (ko'-r&id), the middle, pigmented layer of the eye of vertebrates. 

 Chromosome (kro'-mo-som), heavily staining, rod-shaped body that is seen in 



mitosis; carries genes of heredity. 

 Chromatin (kro'-ma-tin), material in the nucleus that is concerned with 



heredity; stains heavily; forms the chromosomes in mitosis. 

 Cilia (sil'-i-a), tiny hair-like projections usually found in large numbers on 



certain cell surfaces. 

 Circum- (ser'-kum), prefix meaning around. 

 Clavicle (klav'-i-kl), the colar bone. 

 Clitellum (kli-tel'-um), an enlarged ring around the earthworm; secretes the 



cocoon. 

 Clitoris (kli'-to-ris), a small body of erectile tissue at the anterior portion of the 



external genitalia of the higher vertebrate females. 

 Cloaca (klo-a'-ka), a posterior cavity found in many vertebrates that receives 



the waste food, the excretory waste, and the reproductive products and 



empties them all through one external opening. 

 Coccyx (kok'-six), vestige of tail bones in man and apes. 

 Cochlea (kok'-le-a), the coiled structure of the inner ear containing the sensory 



endings of the auditory nerve. 

 Coeliac (se'-ll-ak), pertaining to the abdomen. 

 Coelom (se'-lom), the body cavity lying between the digestive tract and the 



body wall ; it is lined with mesoderm. 

 Commensalism (kom-men'-sal-izm), an association between two living organ- 

 isms in which one benefits, but the other is neither benefited nor harmed. 

 Conjugation (kon-ju-ga'-shtin), a primitive form of sexual reproduction found 



in Paramecium. 

 Copulation- (kop-u-la'-shun), sexual union involving the transference of sperm 



from one animal to another. 



Coracoid (kor'-a-koid), a bone in the pectoral girdle of the frog. 



Cornea (kor'-ne-a), the transparent outer layer at the front of the eye. 



Corpus luteum (kor'-pus lut'-e-um), hormone-producing body on the ovary of 

 pregnant mammals. 



Cortex (kor'-tex), the outer portion of the cerebrum of chordates; the outer 

 portion of the kidney; the outer portion of the adrenal gland. 



Cortin (kor'-tin), hormone secreted by the cortex of the adrenal glands. 



Cretin (kre'-tin), an abnormal person, characterized by physical and mental re- 

 tardation ; may be caused by deficiency of thyroxin in early life. 



Cutaneous (ku-tan'-e-us), pertaining to the skin. 



Cyst (sist), a protective coating developed around the outside of an organism 

 or a part of an organism. 



