GLOSSARY 



681 



O'vi-duct (L. ovum, egg; ducere, to lead). A 

 tube which conveys the eggs from the ovary 

 to the uterus or to the exterior. 



O-vip'a-rous (L. ovum, egg; parare, to pro- 

 duce). Producing eggs which hatch outside 

 the body of the mother; egg-laying animals. 



O'vi-pos'i-tor (L. ovum, egg; ponere, to place). 

 An organ of female insects which aids in 

 the depositing of eggs. 



O'vo-vi-vip'a-rous (L. ovum, egg; vivus, alive; 

 parere, to bear). Producing eggs that hatch 

 within the parent's body but which are not 

 nourished by the mother's blood stream 

 through a placenta. 



O-vu-la'tion (L. ovum, egg). The release of 

 eggs from the ovary. 



O'vum (L., egg). An egg; a nonmotile female 

 gamete. 



Ox'i-da"tion (Gr. oxys, acid). The chemical 

 change in which a molecule loses one or 

 more electrons; sometimes involves combin- 

 ing with oxygen. 



Para-tine (L. palatium, from Palatium, one of 

 the 7 hills of Rome). Bone which serves as 

 an anterior brace of the upper jaw in the 

 skull of the frog and other vertebrates. 



Pa'le-on-tol"o-gy (Gr. palaios, old; ons, being; 

 logos, discourse) . The science that deals with 

 the ancient life of the earth as revealed by 

 fossils, impressions, and other remains found 

 in the strata of the earth's surface layers. 



Palp (L. palpare, to feel). A projecting part or 

 process, sensory in function, often near the 

 mouth. 



Pal'pus (L. palpo, touch). Used mostly for a 

 palp which is a process of an appendage, as 

 in insects. 



Pan'cre-as (Gr. pan, all; kreas, flesh). A diges- 

 ti\e gland which discharges into the intes- 

 tine; it produces digestive enzymes and 

 insulin. 



Pa-pil'la (L., nipple). Any small nipple-shaped 

 ele\ations. 



?ar'a-po"di-um (Gr. para, beside; pous, foot). 

 Flattened, moxable, paired appendages on 

 the body segments of many polychaete an- 

 nelids. 



Pai'a-site (Gr. para, beside; sitos, food; or 

 parasitos, eating beside another). An organ- 

 xsm that lives during the whole or a phase 

 of its life upon or within another organism 



(host) and from which it derives nourish- 

 ment. 



Par'a-sphe"noid (Gr. para, bcjond; sphenoid, 

 wedge, form ) . Bone forming the floor of 

 the cranium of a vertebrate. 



Par'a-thy"roid (Gr. para, near; thyreoeides, 

 shield-shaped). One of several (usually 4) 

 small ductless glands, closely associated with 

 the thyroid gland of the vertebrates. 



Pa-ren'chy-ma (Gr. para, beside; enchyma, 

 infusion). A type of loose, spong\', connec- 

 tive tissue found in some of the inverte- 

 brates; in vertebrates, the specific tissue com- 

 ponent of an organ, such as hepatic cells in 

 the liver. 



Pa-ri'e-tal (L. parietis, wall). Pertaining to the 

 outer wall of the coelom. 



Pa-ri'e-tal bone (L. parietis, a wall. A.S. ban, 

 bone). One of a pair of bones located just 

 posterior to the frontal bones. 



Par'the-no-gen"e-sis (Gr. parthenos, virgin; 

 genesis, origin. The production of offspring 

 from unfertilized eggs. This is unisexual re- 

 production. See Natural parthenogenesis. 



Par'the-no-go-nid"i-um (Gr. parthenos, virgin; 

 gonos, offspring). A cell that produces a 

 miniature colony through asexual methods 

 of multiplication in such forms as the 

 vohox. 



Pa-ter'nal (L. paternus, from pater, father). 

 Pertaining to the father. 



Path'o-gen"ic (Gr. pathos, disease; genesis, 

 production ) . Disease-producing. 



Pa-thol'o-gy (Gr. pathos, disease; logos, studv). 

 The study of abnormal (diseased) struc- 

 tures and abnormal functioning of life proc- 

 esses. 



Pec'to-ral gir'dle (L. plural of pectus, breast. 

 A.S. gyrdel, to encircle). Group of bones 

 and cartilage connecting the forelimb to the 

 axial skeleton in vertebrates. 



Ped'al (L. pes, foot). Pertaining to the feet. 



Ped'i-cel-la'ri-a (L. pediculus, small foot). 

 Small pinccr or scissorlike processes on the 

 surface of certain echinoderms, such as tlie 

 starfishes. 



Ped'i-cle (L. pediculus, little foot). The nar- 

 row waist between the cephalothorax and 

 the abdomen in spiders. 



Ped'i-palp ( L. pes, foot; palpare, to feel ) . 

 Either of the second pair of appendages in 

 Arachnida. They are often sensory and some- 



