HYS- 
structure, formed by the fused 
haemal spines of the last few 
vertebrae, which TEpORs the caudal 
fin in certain Fishes (zo 
hysterogenic (his’ st ty "ik ‘a. [Gk. 
hysteros, \ater ; rth.] Of 
later development or ae (zool.). 
I 
ichthyic page a. [Gk. cchthys, 
fish.] or haaeondc of 
Fishes . ). 
chthyoid (ik’thioid) a.,—ichthyic. 
Guaryaiise (ik’thiolit) [Gk. ichthys, 
sh ; “thos, a cay A fossil fish or 
rt 
ichthyology fio oji) #2 [Gk 
ichth logos, discourse. ] 
That part of zoology treating of 
fishes, 
ichthyopterygia (ik’thidptérij’ia) 7. 
plu. [Gk. ichthys, fish; pleryx, 
wing or fin.] Paired fish fins 
zool, 
icosandrous i a [Gk. 
man.]} ee 
di 
hypothetical structural unit; 
chromomere (cy 
idant (i dint) 1. wT Gk. pi Steam 
unit resulting from aggrega- 
tion of ids ; the chetcicane at. 
idioblast (id’ oe re a 
distinct ; d/asto bud.] bio 
phore ; an ulkimate cell - See 
etical 
the 
idiochromatin id'tokeo bron n, (Gk. 
tdios, distinct ; chroma, colour.] 
Temporarily dormant S egeiive 
chromatin; cf. trophochromatin 
(cyt.). 
idiochromidia (id‘iékrémid’ reg n. plu. 
[Gk. édios, distinct ; chroma, colour.] 
Sporetia ; generative sy A ap 
cf. trophochro 
me (id’ Woke ‘mns0m) n. 
(Gk. dios, distinct ; chroma, colour ; 
soma, body. An additional ‘chromo o- 
served in certain ey cells—one or 
more may be present (cy7.). 
uscular (id'‘iémiis’kular) a, [Gk. 
144 
ILI- 
idios, personal; L. musculus, 
ppl. contraction of a 
rated muscle artificially 
inct ; gine somseth oa 
moul ded] Chromatin ; = ergs 
ive or germinal part o cell ; 
trophoplasm (¢ 
idiosome (id'iésom) #. [Gk. zdios, 
nct; soma, body.] An idio- 
blast or biophore. See hypotheti- 
c _ 
idiothalamous (idiéthal’Amiis) a. 
‘os personal ; eggs 
aa aene — Lichens in 
s parts are differently 
econ pate the thallus (602). 
othermous (id‘iéthér’miis) a, [Gk. 
idios, personal; “‘hermos, hot.] 
War ode hamolotheraal 
zool.). 
idiozome (id'iéz6m) ”. [Gk zdios, 
eon oye 
idorgan Gaer a nm.  [Gk. iar 
tinct ; oxganon, instrument.] A 
purely morphological multicellular 
unit does 
feat as 
eocaecal (il'édsé’kal) a. [L. c/eum, 
groin ; — blind.] Per¢. ile 
and caecum; api. fossae, folds, 
etc. 
ieoeolie {eres k) a. [L. cleum, 
ro anew’ e aad Pert. ileum 
an n; a artery, lymph 
glan — (anat. 
ileum ttt éiim) 7. i tleum, groin.] 
lower a of the small in- 
testine (am 
iliac (il'iak) a. “gi ilia, flanks. ] — 
ilium, a pelvic bone ; a artery, 
fossa, furrow, tuberosity, vein, 
muscle, etc. (avat. 
iliocaudal (il'iéké 6/dal) a. [L. tia, 
anks; ¢auda. 
tail. 
ilium and tail ; 4 nat.) 
iliococeygeal (iliék6k’sijé’4l, -kdksij’- 
él) a. [L. zééa, flanks okkyx, 
cuckoo.] ert. ilium and coccyx ; 
= a muscle (anazé, 
ilioc (iV'i5kds tal) a [L. 
ilia, 
flanks : costa, rib.} In region of 
