TRO- 



333 



TRU- 



trochus (tro'kus) . [Gk. trochos, 

 wheel.] The inner, anterior, coarser 

 ciliary zone of a rotifer disc ; cf. 

 cingulum (zool.). 



tropeic (trope'Ik) a. [Gk. tropis, a 

 keel.] Keel-shaped (zool.). 



trophi (tro'fi) n. plu. [Gk. trophe, 

 nourishment.] The hard chitinous 

 chewing organs of Rotifers ; the 

 mouth-parts of an Insect ; the 

 mandibles and first and second 

 maxillae collectively (zool.). 



trophic (trof'ik) a. [Gk. trophe, 

 nourishment.] Connected with 

 nutrition ; appl, nerves (anat.). 



trophoblast (trof'oblast) n. [Gk. 

 trophe, nourishment ; blastos, bud.] 

 The outer layer of cells of a morula 

 (emb.). 



trophochromatin (trof'okro'matin) n. 

 [Gk. trophe, nourishment ; chroma, 

 colour.] Vegetative chromatin, or 

 that which regulates metabolism 

 and functions ; cf. idiochromatin 

 (biol.). 



trophochromidia (trof'okromid'Ia) n. 

 plu. [Gk. trophe, nourishment ; 

 chroma, colour.] Vegetative chro- 

 midia ; cf. idiochromidia (biol.). 



trophodisc (trofodlsk) n. [Gk. trophe, 

 nourishment ; diskos, a plate.] 

 The female gonophore of certain 

 Hydrozoa (zool.). 



trophology (trofol'qjl) n. [Gk. trophe, 

 nourishment ; logos, discourse.] 

 The science of nutrition (phys.). 



trophonemata (trof'onSm'ata) n. plu. 

 [Gk. trophe, nourishment ; nema, 

 thread.] Uterine villi or hair-like 

 projections of Elasmobranchs, 

 which transfer nourishment to the 

 embryo through the spiracles 

 (zool.}. 



trophonucleus (trof'onu'kleus) n. [Gk. 

 trophe, nourishment; L.. nucleus, a 

 kernel.] The principal nucleus of 

 binuclear Protozoa, regulating meta- 

 bolism and growth ; cf. kineto- 

 nucleus (cyt.). 



trophophore (tr6f'6for) n. [Gk. 

 trophe, nourishment ; pherein, to 

 bear.] In Sponges, an internal 

 bud or group of cells destined to 

 become a gemmule (zool.). 



trophoplasm (trof'oplazm) n. [Gk. 

 trophe, nourishment ; plasma, some- 

 thing moulded.] The vegetative or 



nutritive part of a cell ; cf. idio- 

 plasm (cyt.). 



trophoplast (trof'oplast) n. [Gk. 

 trophe, nourishment ; plastos, 

 moulded.] A cell, nucleated or 

 not ; a plastid (biol.). 



trophosome(trof'6s6m)#. [Gk. trophe, 

 nourishment ; soma, body.] The 

 nutritive polypoid persons of a 

 hydroid colony (zool.). 



trophospongia (trof'ospun'jla) n. 

 [Gk. trophe, nourishment ; sponggia, 

 a sponge.] A spongy vascular 

 layer of mucous membrane between 

 uterine wall and trophoblast (emb.). 



trophospongium (trof'ospSn'jium) n. 

 [Gk. trophe, nourishment ; sponggia, 

 sponge.] Canalization of nerv^ 

 cells, the canaliculi being occupied 

 by branching processes of neuroglia 

 cells (phys.). 



trophotaxis (trof'btak'sls) n. [Gk. 

 trophe, nourishment ; taxis, arrange- 

 ment.] Stimulation by an agent 

 which may serve as food (phys.). 



trophotropism (trofot'roplzm) n. 

 [Gk. trophe, nourishment ; trope, 

 a turning.] Tendency of an or- 

 ganism towards a food supply 

 (biol.). 



trophozoite (trof'ozo'lt) n. [Gk. trophe, 

 nourishment ; zoon, animal.] The 

 adult stage of a Sporozoan (zool.). 



trophozooid (trof'ozo'oid) n. [Gk. 

 trophe, nourishment ; zoon, animal ; 

 eidos, form.] A nutritive zooid of 

 free-swimming tunicate colonies 

 (zool.). 



tropic movement, reactionary 

 movement to certain stimulation 



tropism (tro'pizm) n. [Gk. trope, a 

 turning.] The tendency of an 

 organism to react in a certain way 

 to a certain kind of stimulus ; a 

 tendency to move towards (positive) 

 or away from (negative) a source of 

 stimulus (phys.) ; cf. chemo-, geo-, 

 photo-, tropho-tropism. 



tropophyte (tro'poflt) n. [Gk. trope, 

 a turning ; phyton, a plant.] A 

 changing plant, or one which is 

 more or less hygrophilous in summer 

 and xerophilous in winter (bot.). 



true ribs, ribs which are directly 

 connected with the sternum, as 

 opp. floating ribs. 



