HYS- 



144 



ILI- 



structure, formed by the fused 

 haemal spines of the last few 

 vertebrae, which supports the caudal 

 fin in certain Fishes (zool). 

 hysterogenic (his'terojen'ik) a. [Gk. 

 hysteros, later ; genos, birth.] Of 

 later development or growth (zool.}. 



I 



ichthyic (ik'thnk) a. [Gk. ichthys, 

 fish.] Pert, or characteristic of 

 Fishes (zool.). 



ichthyoid (ik'thioid) a., ichthyic. 



ichthy elite (ik'thidllt) n. [Gk. ichthys, 

 fish ; lithos, stone.] A fossil fish or 

 part of one (pal.). 



ichthyology (ikthiol'oji) n. [Gk. 

 ichthys, fish ; logos, discourse.] 

 That part of zoology treating of 

 fishes. 



ichthyopterygia (ik'thiopterij'ia) n. 

 plu. [Gk. ichthys, fish ; pteryx, 

 wing or fin.] Paired fish fins 

 (zool.). 



icosandrous (I'kosan'drus) a. [Gk. 

 eikosi, twenty ; aner, man.] Having 

 twenty or more stamens (pot.). 



id (id) n. [Gk. idios, distinct.] A 

 hypothetical structural unit ; the 

 chromomere (cyt.). 



idant (1'dant) n. [Gk. idios, distinct.] 

 A unit resulting from an aggrega- 

 tion of ids ; the chromosome (cyt.). 



idioblast (id'ioblast) n. [Gk. idios, 

 distinct ; blastos, bud.] A bio- 

 phore ; an ultimate cell unit. See 

 hypothetical units. 



idiochromatin (id'iokro'matin) n. [Gk. 

 idios, distinct ; chroma, colour.] 

 Temporarily dormant generative 

 chromatin ; cf. trophochromatin 

 (cyt.). 



idiochromidia (id'iokromld'ia) n. plu. 

 [Gk. idios, distinct ; chroma, colour.] 

 Sporetia ; generative chromidia ; 

 cf. trophochromidia (cyt.). 



idiochromosome (id'iokro'mosom) n, 

 [Gk. idios, distinct ; chroma, colour ; 

 soma, body.] An additional chromo- 

 some with a relation to sex, ob- 

 served in certain germ cells one or 

 more may be present (cyt.). 



idiomuscular (id'fomus'kular) a. [Gk. 



idios, personal ; L. musculus, 

 muscle.] Appl. contraction of a 

 degenerated muscle artificially 

 stimulated (phys.). 



idioplasm (id'ioplazm) n. [Gk. 

 idios, distinct ; plasma, something 

 moulded.] Chromatin ; the genera- 

 tive or germinal part of a cell ; cf. 

 trophoplasm (cyt.). 



icliosome (id'iosom) n. [Gk. idios, 

 distinct ; soma, body.] An idio- 

 blast or biophore. See hypotheti- 

 cal units. 



idiothalamous (id'iothal'amus) a. 

 [Gk. idios, personal ; thalamos, 

 receptacle.] Appl. Lichens in 

 which various parts are differently 

 coloured from the thallus (bot.). 



idiothermous (id'iother'mus) a. [Gk. 

 idios, personal ; thermos, hot.] 

 Warm - blooded ; homoiothermal 

 (zool.). 



idiozome (id'ib'zom) n. [Gk. idios, 

 distinct ; zoma, girdle.] In sper- 

 matogenesis a separated portion of 

 archoplasm which ultimately be- 

 comes the head-cap of the sperma- 

 tozoon (cyt.). 



idorgan (idor'gan) n. [Gk. idios, 

 distinct ; organon, instrument.] A 

 purely morphological multicellular 

 unit which does not possess the 

 features of a soma (biol.). 



ileocaecal (H'eose'kal) a. [L. ileum, 

 groin ; caecus, blind.] Pert, ileum 

 and caecum ; appl. fossae, folds, 

 etc. (anat.). 



ileocolic (il'eokol'fk) a. [L. ileum, 

 groin ; kolon, the gut.] Pert, ileum 

 and colon ; appl. artery, lymph 

 gland, etc. (anat.). 



ileum (il'eum) n. [L. ileum, groin.] 

 The lower part of the small in- 

 testine (anat.). 



iliac (Il'lak) a. [L. ilia, flanks.] Pert. 

 ilium, a pelvic bone ; appl. artery, 

 fossa, furrow, tuberosity, vein, 

 muscle, etc. (anat.). 



iliocaudal (Il'ioko'dal) a. [L. ilia, 

 flanks ; cauda, tail.] Connecting 

 ilium and tail ; appl. muscle (anat.). 



iliococcygeal (iliokok'sije'al, -koksij'- 

 eal) a. [L. ilia, flanks ; Gk. kokkyx, 

 cuckoo.] Pert, ilium and coccyx ; 

 appl. a muscle (anat.). 



iliocostal (Tl'fokos'tal) a. [L. ilia, 

 flanks ; costa, rib.] In region of 



