PRO- 



257 



PRO- 



head-kidney of embryonic life, 

 arising from mesomeric somites, 

 functional for a time in lower 

 vertebrates, later replaced by meso- 

 or meta-nephros (emb.~). 



pronotum (prono'tum) n. [Gk. pro, 

 before ; noton, back.] The dorsal 

 part of the prothorax of Insects 

 (zoo/.). 



pronucleus (pronu'kleus) n. [L. pro, 

 before ; nucleus, kernel.] The egg- 

 nucleus or sperm-nucleus during 

 fertilization (emb.}. 



pronymph (pro'nlmf) n. [L. pro, 

 before ; nympha, a maid.] The 

 stage in the metamorphosis of 

 Diptera preceding the nymph stage 

 (zoo/.). 



proostracum (proos'trakum) n. [Gk. 

 pro, for ; ostrakon, a testacean 

 shell.] The horny pen of a deca- 

 pod dibranchiate shell or Belemnite 

 (Pal.\ 



prootic (proot'ik) n. \Gk.pro, before ; 

 ous, ear.] The anterior bone of the 

 otic capsule in vertebrates (zoo/.). 



propagative (prop'aga'tiv) a. [L. 

 propagare, to propagate.] Repro- 

 ductive ; appl. a cell, a phase, an 

 individual of a colony (biol.}. 



propagulum (propag'ulum) n. [L. 

 propagare, to propagate.] A bud 

 or shoot capable of developing into 

 an adult (bot.}. 



propatagium, a prepatagium. 



prophase (prS'faz) n. [Gk. pro, 

 before ; phasis, appearance.] The 

 preparatory changes, the first stage 

 in mitosis (cyt.}. 



prophloem, protophloem. 



prophototropism (pro'fotot'ropizm) n. 

 [Gk. pro, for ; phos, light ; trope, a 

 turning.] Positive phototropism 

 (bot.\ 



prophyllum (profll'iim) n. [Gk. pro, 

 for ; phyllon, leaf.] A small bract 

 (dot.). 



propleuron (proploor'on) n. [Gk. pro, 

 before ; pleura, side.] A lateral 

 plate of the prothorax of Insects 

 (zoo/.). 



propodeon (propo'deon) n. [Gk. pro, 

 before ; pous, foot.] An abdominal 

 segment of Hymenoptera in front 

 of the petiole or podeon ; otherwise 

 the median segment, Latraille's 

 segment, etc. (goo/.). 



propodeum, propodeon. 

 propodlte (pro'podlt) n. [Gk. pro, 

 before ; pous, foot.] In Malacos- 

 traca, the segment of a foot sixth 

 from the body (zoo/.). 

 propodium (propo'dlum) n. [Gk. pro, 

 before ; pous, foot.] The small 

 anterior part of a Molluscan foot 

 (zoo/.). 



propteryglum (pro'tSrij'ium, prop'- 

 tgrij'ium) n. [Gk. pro, before ; 

 pterygion, a little wing.] The fore- 

 most of three basals supporting the 

 pectoral finof Elasmobranchs (zoo/.). 

 propulsive pseudopodium, in some 

 Neosporidia, a pseudopodium de- 

 veloped posteriorly which by its 

 elongation pushes the body forward 

 (zoo/.). 



propupa (propu'pa) n. [L.pro, before ; 

 pupa, a puppet.] A stage in insect 

 metamorphosis preceding the pupa 

 stage (zoo/.). 



propygidium (pro'prjld'ium) n. [Gk. 

 pro, before ; pyge, the rump.] The 

 dorsal plate anterior to the pygidium 

 in Coleoptera (zoo/.). 

 prorachls (prorak'Ts) n. [Gk. pro, 

 before ; rhachis, spine.] The face 

 of Pennatulacea which is sterile and 

 coincides with the asulcar aspect of 

 the terminal zooid (zoo/.). 

 proscapula (proskap'ula) n. [L. pro, 

 before ; scapula, shoulder - blade.] 

 The clavicle (zoo/.). 

 proscolex (prosko'le'ks) n. [Gk. pro, 

 before ; skolex, worm.] A rounded 

 cyst with fluid-filled cavity, a stage 

 in the development of the Tape- 

 worm (zoo/.). 



prosecretin (pro'sekre'tTn) n. \L.pro, 

 before ; secretus, separated.] The 

 precursor of secretin (phys.\ 

 prosencephalon (pr6s'6nkgf'alon, -sef-) 

 n. [Gk. pro, before ; engkephalon, 

 brain.] The telencephalon, or fore- 

 brain (anat.). 



prosenchyma (prose'ng'kima) n. [Gk. 

 pros, near ; engchyma, infusion.] 

 Tissue of prosenchymatous cells, 

 prosenchymatous (pros'gngkim'atus) 

 a. [Gk. pros, near ; engchyma, 

 infusion.] Appl. elongated pointed 

 cells, with thin or thick cell-walls, 

 in plant tissue (bot.}. 

 prosethmoid (prosgth'moid) . [Gk. 

 Pros, near ; ethinos, sieve.] An 

 K 



