548 GLOSSARY 



Chrom'atin (Gr. chroma, color): a stainable constituent of the nucleus. 



Cil'ium (Lat.ci/iicm, an eyelid with eyelashes): a tiny hair-like protoplasmic projection 



attached to the surface of a cell. 

 Cocoon (Lat. concha, shell): the hairy or silken covering of the pupa of some insects; 



the egg case of spiders and earthworms. 

 Coe'lom (Gr. koilos, hollow): the body cavity; location of organs. 

 Coleop'tera (Gr. coleos, sheath; -pteron, wing): an order of insects with hard wing covers 



over the flying or true wings: the beetle. 

 Conjuga'tion (Lat. con, with; jngare, to join): the temporary union of two similar cells 



for the purpose of exchanging nuclear protoplasm. 

 Cor'puscle (Lat. corpusculum, a little body): the floating cells in the blood. 

 Cor'tex (Lat. cortex, bark): the fleshy portion of a root surrounding the central cylinder 



and covered by epidermis. 

 Crusta'cea (Lat. criista, a crust): a class of invertebrates characterized by a hard exo- 



skeleton, as crayfish. 

 Cytoplasm (Gr. kytos, vessel; plasma, anything formed): the form of protoplasm making 

 up the main part of a cell. It incloses the nucleus, and is inclosed by the cell 

 wall. The protoplasm of a cell excluding the nucleus. 

 Den 'tine (Lat. den{t)s, a tooth): the inner portion of a tooth. 

 Dermis (Gr. derma, skin): the true skin, lying beneath the epidermis. 

 Di'aphragm (Gr. diaphragma, a partition wall): the sheet of muscle separating the chest 



cavity from the abdominal. 

 Diges'tion (Lat. digestio, the dissolving of food): the preparing of food for absorption. 

 Dip'tera (Gr. di, twice; pteron, wing): an order of insects having only two wings, as fly 



and mosquito. 

 Ec'toderm (Gr. ectos, outside; derma, skin): the outer layer of cells of animals. 

 Ec'toplasm (Gr. ectos, onts\de; plasma, thing moulded): the outside layer of unicellular 



organisms. 

 Em'bryo (Gr. embryon, an embryo): an organism within the egg membrane. 

 Embryol'ogy (Gr. embryon, an embryo; logos, a talk or discourse): the study of the 



early development of organisms. 

 Encyst'ment (Gr. en, in; kystis, a bladder): the inclosing in a resistant covering; forming 



of a cyst. 

 En'docrine system (Gr. endon, within; krinein, to separate): all the tissues of internal 



secretion; the ductless glands. 

 Endoderm (Gr. endon, within; derma, skin): the inner layer of cells in animals. 

 En'doplasm (Gr. endon, W\\i\{\r\; plasma, substance): the inner portion of the protoplasm 



in unicellular animals. 

 En'dostyle (Gr. endon, within; stulos, pillar): ventral glandular groove in the pharnyx 



of Amphioxus. 

 En'zyme (Gr. en, in; %yme, leaven): a substance secreted by organisms which induces 



chemical changes, as digestion. 

 Ephemer'ida (Gr. ephemeros, for a day): an order of insects which live only a few hours. 

 Epiph'ysis (Gr. epiphusis): the bony disk or pad, derived from a separate center of 



ossification, found at either extremity of limb bones and vertebrae. 

 Epithel'ium (Gr. epi, upon; thele, teat): a sheet of tissue covering or lining a surface. 

 Eryth'rocyte (Gr. eruthros, red; kutos, cell): a red blood-corpuscle. 

 Eugen'ics (Gr. eugenes, well-born): the study of heredity for improvement of off"spring. 



