gastrulation 
animals gastrulation consists in the invagination of the 
blastula, and succeeds blastulation ; in some, as mammals, 
Gastrulation, following Segmentation of the Vitellus or Egg-cleav- 
age of three kinds of HolobTastic Ova, or those which undergo total 
cleavage, seen in perpendicular cross-section through median plane 
of primitive intestinal 
vity : e, outer or epiblastic or ectoderm cells 
, 
(skin-layer), light; t, inner or hypoblastic or endoderm cells (intesti- 
nal layer), dark. (No nutritive yolk in these eggs ; none advanced 
enough to show any mesoblastic cells or mesoderm.) In all, same let- 
ters mark same parts : c, the egg, ovum, cytula, or parent-cell ; f, 
cleavage-cells, biastomeres, or segmentella ; m, mulberry-germ or 
morula ; b, vesicular germ or blastula ; g , germ-cup or gastrula ; s , 
cleavage-cavity, blastoccele, or hollow of blastulatton ; a, primitive 
intestinal cavity, archenteron, or hollow of gastrulation ; o, primitive 
mouth, archaeostoma, or blastopore. Figs. 1-6. Total, equal, and pri- 
mordial egg-cleavage of the lowest true vertebrate (Branchiostoma'}, 
resulting in a pallngenetic or bell gastrula. I, cytula (archicytula); 
2, cleavage stage of 4 cells ; 3, morula (archimorula) of many cells ; 
4, blastula (archiblastula); 5, same undergoing gastrulation by inver- 
sion, invagination, or emboly; 6, gastrula (archigastrula). Figs. 7-11. 
Total but unequal egg-cleavage of an amphibian (frog), resulting in 
a modified or hood gastrula. 7, cytula (amphicytula) ; 8, cleavage 
stage of 4 cells ; o, morula (amphimorula) already in process of blas- 
tulation ; 10, blastula tatnphiblastula) completed ; u, gastrula (am- 
phigastrula), still showing traces of blastular stage. Figs.ia-i?. To- 
tal but unequal egg-cleavage of a mammal (woman), resulting in an- 
other modified amphigastrula or hood gastrula. 12, cytula ; 13, cleav- 
age stage of 2 cells ; 14, same, of 4 cells ; 15, morula beginning to un- 
dergo gastrulation without actual blastulation ; 16, gastrulation fur- 
ther advanced (theoretically corresponding to the blastula? of figs. 4, 5, 
and 10 ) ; 17, gastrulation completed (and to be followed, not preceded 
as in the other cases, by blastulation, or the formation of a blastoder- 
mic vesicle). (From Haeckel's " Evolution of Man.") 
a kind of gastrulation ensues directly upon morulation, 
and therefore precedes blastulation. 
gastmran (gas-tro'ran), n. [< Gr. yaoTv/p 
(yaorp-), stomach, + oiipa, tail, + -aw.] One of 
the gtomatopodous crustaceans. 
G-astrilS (gas'trus), n. [NL. (Meigen),< Gr. ya- 
arfip (yaCTTp-), stomach: see gaster^.'] Same as 
Gasteronhilus. 
gas-washer (g_as'wosh"er), . In gas-making, 
an apparatus into which the gas in process of 
purification is passed from the condenser, and 
which is designed to free the gas from am- 
monia. Several forms of washer have been in use, the 
essential principle of all being the bringing of every parti- 
cle of the gas into intimate contact with water, for which 
ammonia has a strong affinity. The gas passes from the 
washer to the gas-purifier. See also scrubber. 
gas-water (gas 'waiter), n. Water through 
which coal-gas has been passed, and which has 
absorbed the impurities of the gas. It is im- 
pregnated with sulphids and ammoniacal salts. 
gas-well (gas'wel), n. A well or boring from 
which natural gas escapes persistently and in 
considerable quantity. Some borings in western 
Pennsylvania, New York, and Ohio discharge gas enough 
to be of value for heating and illuminating purposes. See 
natural gas, under gas. 
Practically all the large gas-wells struck before 1882 were 
accidentally discovered in boring for oil. Science, V. 521. 
gas-works (gas'werks), n. sing. tuaApl. An es- 
tablishment in which illuminating gas is manu- 
factured, and whence it is distributed by pipes 
to points of consumption. 
gatM (gat). An old preterit of get 1 . 
gat^t, n. An obsolete form of goat. 
gatcn (gach), n. [Pers. gach, Hind, gach, plas- 
ter, mortar.] Plaster as used in Persian gatch- 
work. 
By the aid of gatch or plaster of Paris, the artisan of 
Teheran often transforms these mud structures into 
dreams of loveliness. 
S. G. W. Benjamin, The Century, XXXII. 718. 
gatch-decoration (gach'dek-o-ra"shon), n. In 
Eastern art, especially Persian, decoration in 
molded plaster, by which means designs of great 
boldness can be carried out, even in inexpensive 
work. 
2467 
gatchers (gach'erz), n. pi. [Origin obscure.] 
In mining, after-leavings of tin. Weale. 
gatch-work (gach'werk), n. Work done with 
gatch ; collectively, things produced with gatch- 
decoration. 
gate 1 (gat), n. [< ME. gate, gat, more common- 
ly with initial palatal, gate, gat, geat, get, yate, 
yhate (> mod. E. dial, yate, Sc. also yet, yett), 
< AS. geat (pi. geatu, gatu), a gate, door (= OS. 
gat, a hole (applied to a needle's eye), = OFries. 
gat, jet, a hole, opening (as a breach in a dike), 
= D. gat, a hole, opening, gap, mouth, = MLG. 
LG. gat, a hole, opening, = Icel. gat (pi. got), 
a hole (ef. comp. skrdr-gat, a keyhole, luku-gat, 
a trap-door), = Norw. gat, a hole, esp. a small 
hole made by a knife, a notch, groove (> gata, 
cut a hole, pierce with a knife, esp. of mak- 
ing buttonholes, = Icel. gata, bore (Haldor- 
sen), = Dan. gat, a hole, a narrow inlet) ; per- 
haps < AS. gitan (pret. geat), get, reach: see 
get 1 . Gate 1 is usually confused with gate 2 , a 
way, street, etc., or, if distinguished from it 
etymologically, referred to the same ult. root ; 
but the words are prob. radically different. 
Gate 1 is not represented in HG. or Goth., while, 
on the other hand, gate 2 is peculiar to these 
branches, with the Scand., and does not belong 
originally to any of the LG. tongues.] 1. A 
passage or opening closed by a movable barrier 
(a door or gate in sense 3); a gateway: com- 
monly used with reference to such barrier, and 
specifically for the entrance to a large inclosure 
or building, as a walled city, a fortification, a 
great church or palace, or other public monu- 
ment. 
And Samson . . . took the doors of the gate of the city, 
and the two posts, and went away with them, bar and all. 
Judges xvi. 3. 
Her husband is known in the gates, when he sitteth 
among the elders of the laud. Prov. xxxi. 23. 
All the princes of the King of Babylon came in and sat 
in the middle gate. Jer. xxxix. 3. 
2. Hence, any somewhat contracted or difficult 
means or avenue of approach or passage ; a 
narrow opening or defile : as, the Iron Gates of 
the Danube. 
And in the porches of mine ear did pour 
The leperous distilment ; whose effect 
Holds such an enmity with blood of man, 
That, swift as quicksilver, it courses through 
The natural gates and alleys of the body. 
Shak., Hamlet, i. 5. 
3. A movable barrier consisting of a frame or 
solid structure of wood, iron, or other material, 
set on hinges or pivots in or at the end of a 
passage in order to close it. Specifically (a) A 
swinging frame, usually of openwork, closing a passage 
through an inclosing wall or fence : in this use distin- 
guished from door, which is usually a solid frame closing 
a passage to a house or room, (b) A massive barrier clos- 
ing the entrance to a fortification or other large building, 
as a factory, designed for the passage of vehicles, masses 
of persons, etc. : equivalent to door, 1, but rarely so used, 
except with reference to a door of great size or elaborate 
construction, as the entrance-doors of a cathedral. 
ere war Sett opyn And thanne we went all to the Mownte 
Syon to Dyner. Torkington, Diarie of Eng. Travel], p. 45. 
Open the temple gates unto my love, 
Open them wide that she may enter in. 
Spenser, Epithalarnion, 1. 204. 
(c) The movable framework which shuts or opens a passage 
for water, as at the entrance to a dock or in a canal-lock. 
4. In coal-mining, an underground road con- 
necting a stall with a main road or inclined 
plane. Also called gate-road, gateway. [Eng.] 
5. In founding: (a) One of various forms 
of channels or openings made in the sand or 
molds, through which the metal flows (pouring- 
gate), or by means of which access is had to it, 
either for skimming its surface (skimming-gate) 
or for other purposes. (6) The waste piece of 
metal cast in the gate, (c) A ridge in a casting 
which has to be sawn off. 6. In locksmithing, 
one of the apertures in the tumblers for the 
passage of the stub. . E. H. Knight. 7. A sash 
or frame in which a saw is extended, to prevent 
buckling or bending. -Cilician Gates. See Cili- 
cian. Gate Of justice, a gate, as of a city, temple, etc., 
at which a sovereign or judge sat to receive complaints 
and administer justice. In some places, in observance of 
this custom, special structures following the general form 
of gates may have been erected to receive the throne of 
the justiciary. In the early middle ages, in various regions 
of Europe, as in southern France and in Italy, it was the 
custom for the king or the feudal lord to administer jus- 
tice seated at the gates of the chief church ; whence the 
expressions, with reference to judicial sentences, "at the 
gates," or "at the lions," in allusion to the sculptured 
lions with which the church gates were commonly adorned, 
as at the cathedral of St. Trophimus in Aries. Compare 
Sublime Porte, under Porte. 
gate 
Nor can it be doubted that this [a ruin at Persepolis] is 
one of those buildings so frequently mentioned in the Bi- 
ble as a gate, not the door of a city or buildings, but a 
gate of justice, such as that where Mordecai sat at Susa. 
J. Fergmson, Hist. Arch., I. 193. 
Gates of death. See death's door, under death. Ivory 
gate, in poetical imagery, the semi-transparent gate of 
the house of Sleep, through which dreams appear distort- 
ed so as to assume flattering but delusive forms. The 
other gate is of transparent horn, through which true vi- 
sions are seen by the dreamer. The allusion is to a legend 
in Greek mythology. 
Two gates the silent house of Sleep adorn, 
Of polish'd ivory this, that of transparent horn : 
True visions through transparent horn arise; 
Through polish'd ivory pass deluding lies. 
Dryden, XneiA, vi. 
Let it suffice me that my murmuring rhyme 
Beats with light wing against the ivory gate, 
Telling a tale not too importunate 
To those who in that sleepy region stay. 
William Morris, Earthly Paradise, I., Apol. 
The angelic door or gate. See door. The beautiful 
gates, royal gates, silver gates. See the royal doors, 
under door. To break gates, in English universities, 
as Cambridge and Oxford, to enter college after the hour 
to which a student has been restricted a serious offense. 
See gat el , t>. , 2. To stand in the gate or gates, in Scrip. , 
to occupy a position of advantage or defense. 
Stand in the gate of the Lord's house, and proclaim there 
this word. Jer. vii. 2. 
gate 1 (gat), v. t. ; pret. and pp. gated, ppr. gat- 
ing. [< gate 1 , .] 1. To supply with a gate. 
2. In the English universities of Oxford and 
Cambridge, to punish by a restriction on cus- 
tomary liberty. An undergraduate may be gated for 
a breach of college discipline either by having to be with- 
in his college-gates by a certain hour, or by being denied 
liberty to go beyond the gates. 
The dean gave him a book of Virgil to write out, and 
gated him for a fortnight after hall. 
T. Hughes, Tom Brown at Oxford, xii. 
gate 2 (gat), n. [Also, and in the particular sense 
' manner of walking, walk,' now usually spelled 
gait, but prop, gate, < ME. gate (never with in- 
itial g, y, being of Scand. origin), a way, road ; 
fig. , in certain adverbial phrases, way, manner 
(as in what gate, in what manner, other gate or 
other gates, in other manner (see another-gates), 
no gates, in no wise, alle gate, nlgates, always, 
at all events (see algate), thus gate, thus gates, 
in this manner, thus, so gate, so gates, in such 
manner, so, how gates, how, etc.); < Icel. gata, 
a way, path, road (in phrase alia gotu, algates, 
always, throughout), = Norw. gata, a road, path, 
driveway, street, = Sw. gata, a street, lane, = 
Dan. gade, a street, = OHG. gazza, MHG. gazze, 
G. gasse, a street, = Goth, gatwo, a street. 
Usually confused with gate 1 , a door, but the 
connection, if any, is remote: see gate 1 . A 
popular association with go (Sc. gae) has given 
special prominence to the particular sense 3, 
' manner of walking, walk,' with senses thence 
derived, usually spelled gait; but there is no 
etymological connection with go.] 1. Away; 
road; path; course. [Now chiefly Scotch, and 
also spelled gait.~\ 
Thou canst [knowest] ful wel the ricthe [right] gate 
To Lincolne. Bavelok, 1. 846. 
Als foghel fleghand [as flying fowl] . . . 
Of whase gate men may no trace fynd. 
Hampole, Flick of Conscience, 1. 7075. 
On the gate we mette of thyne stronge theves sevene. 
Sir Ferumbras, 1. 1801 (Early Eng. Metr. Horn., ed. Ellis). 
I was going to he an honest man ; but the devil has this 
very day flung first a lawyer, and then a woman, in my 
gate. Scott. 
I gaed a waefu' gate yestreen, 
A gate, I fear, I'll sadly rue. 
Burns, I gaed a waefu' gate yestreen. 
[In this sense it is common in names of streets, as High- 
gate, Bishopsr/ate, Gallow^ate, Kirkgate, etc., where gate is 
often understood to represent gatei, a door or entrance.] 
2. Way; manner; mode of doing: used espe- 
cially with all, this, thus, other, no, etc., in ad- 
verbial phrases. [Now only Scotch.] 
Sule ye thus gate fro me fle ? 
Havelok, 1. 2419. 
None other gates was he dighte, 
Bot in thre gayt [goat] skynnes. 
Sir Perceval, 1. 658 (Thornton Rom., ed. Halliwell). 
Gae wa, lad ; dinna blaw in folks' lugs that gate. 
Scott, Redgauntlet, letter xii. 
In particular 3+. Way or manner of walk- 
ing ; walk ; carriage. [In this use now spelled 
gait, and usually associated (erroneously) with 
the verb go. See the etymology, and gait.~] 
4f. Movement on a course or way; progress; 
procession; journey; expedition. 
Than Schir Gawine the Gay 
Prayt for the journay, 
That he might furth wend. 
The king grantit the gait to Schir Gawayne. 
Gawan and Gologras, Hi. 12. 
