BIT- 



34 



BLA- 



Appl. the two temporal bones ; a 

 line joining the posterior ends of the 

 two zygomatic processes (attaf.). 



biternate (blteVnat) a. [L. bis, twice ; 

 terni, three by three.] Ternate 

 with each division itself again 

 ternate (bot.}. 



bivalent (biva'lgnt, biv'algnt) a. [L. 

 bis, twice ; valere, to be strong.] 

 Appl. a double chromosome (cyt.}. 



bivalve (bl'valv) a. [L. bis, twice ; 

 valvae, folding doors.] Consisting 

 of two plates or valves, as a mussel 

 shell (zool.} ; or a seed-capsule of 

 similar structure (bot.}. 



biventer cervlcis (biven'tgr servl'sls) n. 

 [L. bis, twice ; venter, belly ; cervix, 

 neck.] A muscle of the neck con- 

 sisting of two fleshy broad ends 

 with a narrow tendinous portion in 

 the middle (anat.}. 



biventral (blvSn'tral) a. [L. bis, twice; 

 venter, belly.] Appl. muscles of the 

 biventer type (anat.}. 



bivittate (bivit'at) a. [L. bis, twice ; 

 vitta, band.] With two oil re- 

 ceptacles (bot.} ; with two stripes 



bivium (blv'lum) n. [L. bis, twice ; 

 via, way.] Generally the posterior 

 pair of ambulacral areas in certain 

 Echinoidea ; the two rays between 

 which the madreporite lies (zool.}. 



bladder (blad'er) n. [A.S. blaedre, 

 bag.] A membranous sac filled 

 with air or fluid (bot., zool.}. 



bladder-worm stage, the cysticercus 

 stage in tapeworms (zool.}. 



blade (blad) n. [A.S. blaed, leaf.] The 

 flat part of the leaf of grasses 

 (bot.}. 



blastaea (blaste'a) n. [Gk. blastos, 

 bud.] A planaea or ciliated planula, 

 a hypothetical stage in evolution 

 (biol}. 



blastelasma (blas'tglaz'ma) n., blastel- 

 asmata (blas'teiaz'mata) plu. [Gk. 

 blastos, bud ; elasma, plate.] Any 

 germ layer formed after the forma- 

 tion of the epiblast and hypoblast 

 (etnb.}. 



blastema (blaste'ma) n., blastemata 

 (blaste'mata) plu. [Gk. blastema, 

 bud.] The formative substance in 

 an egg ; the primordium of an 

 organ (etnb.}; the thallus of a lichen 

 (bot}. 



blastocarpous (blas'tokar'pus) a. [Gk. 

 blastos, bud; karpos, fruit.] De- 

 veloping while still surrounded by 

 the pericarp (bot.}. 



blastocheme (blas'tokem) n. [Gk. 

 blastos, bud ; ochema, vessel.] A 

 reproductive individual in some 

 Medusae (zool.}. 



blastochyle (blas'tokll) n. [Gk. blastos, 

 bud ; chylos, juice.] The fluid in a 

 blastocoel, or segmentation-cavity 

 (zool.}. 



blastocoel (blas'tosel) n. [Gk. blastos, 

 bud ; koilos, hollow.] The segmenta- 

 tion-cavity of a developing ovum 

 (emb.}. 



blastocolla (blas'tokol'a) n. [Gk. 

 blastos, bud ; kolla, glue.] A gummy 

 substance coating certain buds (bot.}. 

 blastocyst (blas'tosist) . [Gk. blastos, 

 bud ; kystis, bladder.] The germinal 

 vesicle (emb.}. 



blastoderm (blas'toderm) n. [Gk. 

 blastos, bud ; derma, skin.] The 

 germinal disc (smb.}. 

 blastodermic vesicle, ahollow sphere 

 of cells, an earlystage in the develop- 

 ment of a fertilized ovum (emb.}. 

 blastodisc (blas'todisk) n. [Gk. blastos, 

 bud ; diskos, disk.] The germinal 

 area of a developing ovum (emb.}. 

 blastogenesis (blas'tqjen'esls) n. [Gk. 

 blastos, bud ; genesis, birth.] Gem- 

 mation or reproduction by bud- 

 ding ; transmission of inherited 

 characters by means of the germ- 

 plasm only (biol.}. 



blastogenic (blas'tqjen'ik) a. [Gk. 

 blastos, bud ; genos, offspring.] 

 Appl. inactive idioplasm unalter- 

 able till time and place of activity 

 are reached (emb.}. 



blastomere (blas'tomer) n. [Gk. 

 blastos, bud ; meros, part.] One of 

 the cells formed during the primary 

 divisions of an egg (emb.}. 

 blastoneuropore (blas'tonu'ropor) n. 

 [Gk. blastos, bud ; neuron, nerve ; 

 poros, passage.] A temporary 

 passage connecting blastopore and 

 neuropore (emb}. 



blastophore (blas'tofor) n. [Gk. blastos, 

 bud \pherein, to bear.] Embryonic 

 origin of plumule (bot.} ; in Alcypn- 

 aria the reproductive body, giving 

 rise usually to buds ; the central 

 part of the spermocyte mass in 



