436 (THORDATE ANATOMY 



camassial teeth. The last upper premolar and the first lower molar tooth of carnivora. 



carnivorous. Flesh-eating animals. 



carpus. The wrist. 



cartilage. An elastic connective tissue with cells embedded in a homogeneous matrix. 



castrate. To remove the testes. 



catalyzer. A substance which by its presence changes the velocity of a chemical 



reaction. 

 caudad. Toward the tail. 



cecum. That diverticulum of the colon into which the vermiform appendix opens, 

 cenogenetic. Of recent, as contrasted with ancestral, origin. 

 centrum. The body of a vertebra. 

 cephalic. Pertaining to the head. 



cerebellxmi. The little brain, a coordinating center above the fourth brain ventricle, 

 cerebrum. The chief division of the brain. 

 cheiropterygium. The skeleton of the fingered appendage. 

 chemoreceptor. A sensory cell which responds to chemical stimulation. 

 chiasma. A decussation or x-shaped crossing of nerve fibers within the central nervous 



system. 

 chief cells. The pepsinogen secreting cells of the gastric glands. 



chitin. The hornynitrogenous substance which forms mostof the skeletonsof arthropods, 

 choana. A funnel-shaped opening. 



cholesterol. A fat-like substance which forms the usual type of gallstones. 

 chondrin. A gelatin-like protein found in cartilage. 

 chorda dorsalis. The notochord, the primary chordate axial skeleton. 

 chorda tympani. A mixed branch of the facial nerve. 

 chordae tendineae. The tendons of the heart-valves. 

 chorio-allantois. The fused membranes of the allantois and chorion. 

 chorioid (choroid). A chorion-like vascular membrane. In the eye a layer between 



retina and sclera. 

 chorioid fissure. A defect in the optic cup and a groove along the optic stalk. 

 chorion. The outer protective extra-embryonic membrane of amniotes. 

 chromaffin cells. Cells of sympathetic origin having an affinity for chrome salts, 

 chromatophore. A pigment cell. 



chyme. The partly digested material which passes from the stomach to the duodenum, 

 ciliary body. A local thickening of the choroid layer of the eye to which the lens is 



attached. 

 cingulvmi. An association fiber tract which encircles the corpus callosum near the 



median plane. 

 cistema chyli. A receptacle or enlargement at the lower extremity of the thoracic 



duct. 

 Clarke's column. A tract of nerve cells in the dorsal column of gray matter of the 



cord, 

 cleft palate. Congenital fissure in the roof of the mouth. 

 cleithrum. A membrane bone of the shoulder girdle of fishes and amphibia, 

 clitoris. An erectile organ of the female homologous with the penis. 

 cloaca. The cavity into which digestive and urogenital organs open. 

 cochlea. The spiral tube of the inner sensory ear. 



celiac (solar) plexus. A large sympathetic plexus in the epigastric region. 

 coelom. The chordate body-cavity. 



coelomoducts. Paired segmental reproductive ducts of annelids. 

 collagen. The chief organic constituent of bone and connective tissue. 

 collateral. A side branch of an axon. 



