GENERAL ZOOLOGY 



BROOD POUCH. Any cavity, other than a part of the reproductive tract, in which 

 esjsjs or youne; are received and retained during at least a part of the develop- 

 mental period. 

 BUCCAL. Pertaining to the mouth. 



BUDDING. A method of asexual reproduction by unequal cell division, as in uni- 

 cellular organisms, or by repeated divisions of totipotent cells to form an out- 

 growth, as in the coelenterates. 



CAECUM [fil. CAECA). A blind pouch attached to any part of a digestive tract. 



CALCAREOUS. Containing lime; chalky. 



CAPILLARY. One of the many minute, thin-walled blood vessels found in organs of 

 the body; substances enter and leave the blood through the walls of such vessels. 



CARDIAC. Pertaining to or situated near the heart. 



CARNIVOROUS. Feeding upon animals. CJ. HERBIVOROUS and OMNIVOROUS. 



CASTE. Any one of the distinct forms of one species found among the social insects, 

 such as the termites. 



CATABOLISM. Collective term for energy-yielding reactions of cellular metabolism. 

 CJ. ANABOLISM. 



CAUDAL. Pertaining to or situated toward the tail. 



CAUSE. The set of conditions as a result of which something occurs; frequently used 

 for what is considered to be the most important of these conditions. 



CELL. A mass of protoplasm containing one or more nuclei at some stage in its dif- 

 ferentiation; the unit of structure and function in animals and plants. 



CELL DIFFERENTIATION. The formation of tissue cells and gametes during histogenesis 

 and gametogenesis, respectively; characterized by changes in the cytosome, or 

 in the nucleus, or in both. 



CELL DIVISION. The method of origin of new cells from pre-existing ones. 



CELL LOCALIZATION. The bringing of groups of cells into definite positional relation- 

 ships with other cell groups; brought about by cell movements. 



CELL PRODUCTS. Non-cellular materials built up within cells and passing out of 

 cells. 



CELL SPECIALIZATION. The formation of different kinds of somatic cells associated 

 with a physiological division of labor during the evolution of organisms; some- 

 times used to mean cell differentiation. 



CELLULAR. Consisting of or pertaining to cells. 



CELLULAR RESPIRATION. General term covering the utilization of oxvgen in cellular 

 metabolism. CJ. METABOLISM, CATABOLISM, and RESPIRATION. 



CENTIMETER. The hundredth part of a meter; 1 inch equals 2.54 centimeters. 



CEPHALIC. Pertaining to or situated toward the head. 



CEPHALIZATION. The localization of important parts, such as the sense organs and 

 the central nervous system, toward or in the head region during evolution. 



CEPHALOTHORAX. A body division formed by the fusion of the head and the thorax 

 in some of the arthropods. 



CHEMICAL COORDINATION. Coordination brought about by the reaction of cells to 

 the stimuli produced by endocrines that circulate in the blood. Cf. COORDI- 

 NATION and NERVOUS COORDINATION. 



CHEMORECEPTOR. A receptor sensitive to chemical compounds in solution. 



CHITIN. rhe chemical compound characteristic of the exoskeletons of arthropods. 



CHLORAGOGUE LAYER. Outer layer of the stomach-intestine of the earthworm and 

 some other annelids, consisting of the highly modified visceral peritoneum. 



CHLOROPHYLL. The green coloring matter of green plants, occurring also in plant- 

 like flagellate protozoans. 



CHLOROPLAST. An intracellular pigment body, characteristic of plant-like flagellate 

 protozoans, containing the green pigment chlorophyll. CJ. CHROMATOPHORES. 



660 



