GLOSSARY 563 



colony. An association of individuals descended from a common ancestor and 



remaining in organic connection. 

 com- (k6m). L.; with, together, 

 commensalism (k6 mgn' sal Iz'm). An association of two animals of different species 



in which one is benefited and the other not affected. 

 commissure (kom' I shoor). A bundle of nerve fibers connecting two nerve centers 



and crossing the median line. 

 Comstock (kiim' stok), John H. American entomologist; 1849-1931. 

 conditioned reflex. A reflex act which is modified by impulses arising in a "higher" 



nerve center, one which dominates the center in which the adjustor neurons 



involved in the reflex arc are located, 

 conductivity. The property of protoplasm which enables it to transmit the effect of a 



stimulus from one point to another. 

 congenital (kon jcn' I tal). Existing at birth. 

 conjugation (k6n joo ga' shiin). A temporary union of two cells resulting in an 



exchange of material. 

 connective. A bundle of nerve fibers uniting two ganglia on the same side of the body, 

 contractile vacuole (kon trak' til vSk' u 61). A vacuole in a protozoan which alter- 

 nately fills and empties. 

 convergence (kon vur' j?ns). Resemblance between two unrelated types because of 



living under similar conditions. 

 copulation (kop u la' shun). Temporary union of a male and female animal involving 



the passage of sperm cells from the former to the latter. 

 corium (ko' rl lim). The dermis, or connective tissue layer, in the skin of vertebrates, 

 com (korn). L.; horn. 

 cornea (kor' ne a). A sheet of transparent epithelial tissue admitting light to an eye; 



adj., corneal, 

 corp (korp). L.; body. 

 cortex (kor'ti^ks). An outer layer; the outer dorsal layer of the cerebrum and 



cerebellum of higher vertebrates when it is organized into layers and areas; adj., 



cortical, 

 cranium (kra'nium). The cartilaginous or bony box surrounding the brain of 



vertebrates; adj., cranial, 

 crop. An enlargement of an anterior part of the alimentary canal serving for the 



temporary storage of food. 

 cross-fertilization. The fertilization of the egg cell of one animal by the sperm cell 



of another. 

 crossing over. The transfer of genes from one chromosome to another during 



synapsis. 

 cutaneous (ku ta' nc Gs). Pertaining to the skin. 

 cuticle (ku' ti k'l). The epidermal layer of the skin of a vertebrate; also the firm 



outer layer of a protozoan; sometimes used in the same sense as cuticula; adj., 



cuticular (kfi tik' u lar). 

 cuticula (kfitlk'ula). A hard covering on an animal body secreted by the epi- 

 thelium. 

 Cuvier (ku vya'), Georges L. C. F. D. French naturalist; 1769-1832. 

 cyclosis (si klo' sTs). A continued regidar movement of endoplasin within a cell, 

 cyst (sTst). A hard covering secreted around a mass of living matter; adj., cystic, 

 cysticercus (sis tl stir' ktis) . The encysted stage in the development of a 



tapeworm. 

 C5rt (sit). Cr.; a hollow ves.sel; in biology, a cell, 

 cytoplasm (si' to plaz'm). The protoplasm of a cell outside the nucleus; adj., cjrto- 



plasmic (si to plSz' mik). 



