HYD 



205 



HYD 



coenosarc of the Physophoridse, 

 and termed feelers. 



Hydrodictyon, n., hid'-ro-dik'ti-tin 

 (Gr. hudor, water ; diktuon, a 

 fishing-net), a genus of plants, 

 Ord. Algae or Hydrophyta, so 

 named from the reticulated struc- 

 ture of the plants : Hydrodictyon 

 utriculatum, ut-rik'-ul-at'-um (L. 

 utriculus, a small skin or leathern 

 bottle), a species called 'water 

 net, ' which has the appearance of 

 a green net composed of filaments 

 enclosing pentagonal and hexag- 

 onal spaces. 



hydroecium, n., hid-re'shi-um (Gr. 

 hudra, a water serpent ; oikos, a 

 house), the chamber into which 

 the coenosarc in many of the 

 Calycophoridse can be retracted. 



hydrogen, n. , hid'ro-jen (Gr. hudor , 

 water ; gennao, I produce), a 

 metal which, in its gaseous 

 form, is the lightest of all 

 known bodies, producing water 

 when combined with oxygen : 

 sulphuretted hydrogen, a com- 

 bination of hydrogen with 

 sulphur, producing a gas having 

 a smell like rotten eggs, found as 

 a constituent of mineral waters. 



Hydroida, n. plu., hid-royd'-a (Gr. 

 hudra, a water snake ; eidos, re- 

 semblance), in zool, the sub- 

 class of the Hydrozoa which com- 

 prises the animals most nearly 

 allied to the hydra ; in geol. , an 

 extensive genus of zoophytes. 



hydrometra, n., hid'ro-met'ra 

 (Gr. hudor , water ; metra, womb), 

 an excessive secretion and accum- 

 ulation of fluid within the cavity 

 of the uterus. 



hydronephrosis, n., hid'-rd-ntf- 

 roz'is (Gr. hudor, water ; nephros, 

 kidney), dropsy of the kidney, 

 caused by any permanent obstruc- 

 tion of the ureter. 



hydropathy, n., hid-r8p'>ath-i (Gr. 

 hudor, water ; pathos, feeling), 

 the water cure : hydropathic, a. , 

 hid'- ro -path' ik, relating to the 

 water care. 



hydropericardium, n., hld'-ro-ptr- 

 i'kdrd'i-um (Gr. hudor, water ; 

 peri, round about ; kardia, the 

 heart), an eifusion of serum into 

 the sac of the pericardium or 

 membrane enclosing the heart ; 

 dropsy of the pericardium. 



hydrophobia, n., hld'-rd-fob'-l-a 

 (Gr. hudor, water ; phobos, fear, 

 dread), a disease occurring in the 

 human being after being bitten 

 by any rabid animal, characterised 

 by an aversion to water, and 

 more or less general convulsions. 



Hydrophyllacese, n. plu., Jild'-ro- 

 fil'la'-s&e (Gr. hudor, water ; 

 phullon, a leaf), the Hydro - 

 phyllum family, an Order of 

 trees and herbaceous plants, many 

 of which have showy flowers, and 

 some have glandular or stinging 

 hairs : HydrophyllesB, n. plu., 

 hld'-ro-fim-e, a Sub-order : Hyd- 

 rophyllum, n., kSd'-rG-fti'-ltim, a 

 genus. 



Hydrophyllia, n. plu., hid'rd-fiV* 

 li-d (Gr. hudra, a water snake ; 

 phullon, a leaf), in zool., over- 

 lapping appendages or plates 

 which protect the polypites in 

 some of the oceanic Hydrozoa ; 

 also termed ' bracts. ' 



Hydrophyta, n. plu., hld-rof-tt-a 

 (Gr. hudor, water; phuton, a 

 plant), the Sea-weed family ; the 

 Algse or cellular plants found 

 both in salt and in fresh water : 

 hydrophyte, n^hid'rd-ftt, a plant 

 which lives and grows in water 

 only. 



hydrorhiza, n., hid'-ro-rlz'-a (Gr. 

 hudra, a water snake ; rhiza, a 

 root), in zool., the adherent base 

 or proximal extremity of any 

 hydrozobn. 



hydrosoma, n., hld^rd-som'd (Gr. 

 hudra, a water snake ; soma, 

 body), in zool. , the entire organ- 

 ism of any hydrozoon. 



hydrosulphuret, n., hid'-rd-sul/' 

 ur-H (Eng. hydrogen and sul- 

 phur], a compound of hydro- 

 sulphuric acid with a base : hyd- 



