ARA- 
tissue consisting of thin-walled 
um (araknidiiiim) #. [Gk. 
arackite spider. ] he spinning 
apparatus of a spider, including 
spinning-glands and _ spinnerets 
(zool.). 
—, (a rak’noid) a. [Gk. arach- 
eidos, form.] Like a 
é, spider ; 
“ ob 
web ; consist ing of fine en- 
rages a resembling a cobweb 
= of 
(0t.); @ in membrane 
the ce ae ervous system, com- 
posed of Jeteases connective tissue 
pert, or serrated = spider age ). 
rescent (4r’borés’ént) a. [L. 
in te a eee) 
arbor, 
e; Gk. efdos, like.] Tree- like, 
designating ge —— structure of a 
protozoan oe 
r vitae 
a a the ‘cerebellum in vertical 
section (ana 
butean ‘arbi tein) a, [L. arbutus, 
rawbe -| Of or Pert. the 
steeebeery ee (b07.). 
e (4rkad’) 7. [L. arcus,a bow.] 
An varcad channel or J by 
bony arch, as nd 
_ temporal arches in the skull (anat), 
ha es (Ar’kédsits) 2. flu. [Gk 
archaios, ancient ; ky tos, 
Cells arising from u 
psec and ultimately giving 
germ- -cells and gametes 
pe , 
haeostomatous (Ar’kédstém‘atiis) a. 
[Gk. archaios, primitive; stoma, 
Vv 
archi, ones first; L. centrum 
centre.] Centra fo rmed by fusion 
of basal g grow cualia 
external to chordal sheath ; of. 
chordacentra 
archebiosis (av kebie’sts) nm (Gk. 
gga sega aay 
archiblast (Arkibldst) 7. 
archichlamyd 
archicoel (Ar’kisél) 2 
ARC- 
arche, beginning ; dios, life.] The 
origin of life (dz0/.). 
re (ar’kego’ come - 
[Gk. arche, pelea. ng; gono 
spring ; sae 
of mosses caring ele (d0t.), 
Gk. 
archegonium (Ar’kégd’niiim) 7 
arche, beginning ; | mo offspring. 
A female or. 
gaaptieres are ieaied,, an od i in w 
the young rete begins its pees 
ment 
anon (arkén’térén) 7”. [Gk. 
arche, beginning ; aes ron, gut. ] 
The cavity of the gastrula which 
forms ae primitive ae of the 
embryo 
sirttieapte (hs laine n. ([Gk. arche, 
agit ing; sporos, seed.] 
tetrahedral or ie appease cell of 
a sporangium (40 
archiamphiaster (Av kidim' fis! tér) n. 
[Gk. archi, first; amphi, on both 
“tm aster, star. | 
forming the first 
body in cell maturation (cyz). 
[Gk. archi, 
Egg 
first ; d/astos, bud.] proto- 
plasm. 
archiblastic ring hae a. [Gk. 
archi, first ; das. Having 
archiblastula (Arkiblas’tila) 7. 
archi, first ; blastos, bud.] a 
hollow ball of cells derived from a 
total and equal se ook eater OG. 
Gk 
egg with total and equal sepabiee: 
tion (cyz) 
( k. archi, 
first ; Aarpos, fruit.] ie spirally 
rebrum kis sérébrim) 7, 
“"rGk. part first ; L. cerebrum, pro 
The primitive br rain, as the supra- 
1 ganglia of higher 
Invertebrates (z0o/.). 
eous (Av kiklimid’é iis) a. 
[Gk. archi, wee ; chlamys, cloak.] 
Having no petals, or having petals 
entirely jokin from one another 
[Gk. archi, 
first ; pe hallow’ The primary 
body-cavity or space between the 
svimsenttley anal and ectoderm in 
deve Fe Sin “of various groups of 
animals (zoo/.). 
