334 GLOSSARY 



proximal, AroVsimal (L. proximus, nearest), situated near the place of 



attachment. 

 pseudopodium, sii do po'di um (Gr. pseudes, false ; pous, foot), a temporary 



protrusion of the protoplasm in certain animals. 



pupa,/w'/tf (L.pupa, a doll), a stage in the life cycle of certain insects. 

 pyloric, pilor'ik (Gr. pulorus, a gate-keeper), of or pertaining to the orifice 



between the stomach and the intestine, 

 pyrenoid, ptre'noid (Gr. puren, the stone of fruit; eidos, form), a small 



colorless mass of proteid. 



reaction, re ak'shon, the response to a stimulus. 



recapitulation, re ka pit u Id 1 shon (L. re, again; capituluui, a head), a 



theory that holds that the individual in its development passes through 



the ancestral stages of the race (see p. 228). 

 reduction, reditk'shon (L. re, back; ductus, led), the halving of the number 



of chromosomes in the germ nuclei during maturation. 

 reflex, re'Jleks (L. re, back ; /exits, bend), bent back (see p. 302). 

 regeneration, rejen e rd'shon (L. re, again; genero, I beget), the renewal of 



a portion of lost or removed tissue. 

 respiration, res pi rd'shon (L. re, back; spiro, I breath), the absorption of 



oxygen and excretion of carbon dioxid. 

 rostrum, ros'trum (L. rostrtim, a beak), a beaklike structure. 



saltation, sal ta' shon (L. saltatio, dance), an abrupt transition or change. 



saprophytic, saprdfit'ik (Gr. sapros, putrid; phytos, a plant), living on de- 

 caying substances. 



scaphognathite, skafognSthit (Gr. skaphe, a boat ; gnathos, a jaw), a plate 

 which bales the water out of the branchial chamber of the crayfish. 



schizogony, skizog'oni (Gr. schizo, I cleave), reproduction by splitting. 



secretion, sekre'shon (L. secretus, separate), the process of separating sub- 

 stances by glandular activity. 



senescence, se nes'ens (L. senex, old), the condition of growing old. 



sensory, sen 1 so ri (L. sensus, sense), capable of receiving or transmitting im- 

 pressions from without. 



septum, septum (L. septum, a partition), a wall separating two cavities. 



seta, se'td (L. seta, a thin, stiff hair), bristles, or stiff hairs. 



sexual, sek'su al (L. sexus, sex), of or pertaining to sex ; done by means of 

 the two sexes, male and female. 



sinus, si'nus (L. sinus, hollow), a cavity or hollow in tissue. 



somatic, somat'ik (Gr. soma, body), of the body; applied to cells that do 

 not take part in reproduction. 



somite, so'mtt (Gr. soma, body) , a segment of an articulated body. 



