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That part of blastoderm where the hypoblast appears like a small disk on the inner face of the epibladst.

he blastopore) which leads into the cavity (the archenteron) lined by the inner wall (the hypoblast). See Illust. under Invagination. In a more general sense, an ideal stage in embryonic development. See Gastræa. -- a.

lly; glutinous material obtained from animal tissues by prolonged boiling. Specifically (Physiol. Chem.), a nitrogeneous colloid, not existing as such in the animal body, but formed by the hydrating action of boiling water on the collagen of various kinds of connective tissue (as tendons, bones, ligaments, etc.). Its d…

Animals which increase by budding, as hydroids.

One of the imaginary granules or atoms which, according to Darwin's hypothesis of pangenesis, are continually being thrown off from every cell or unit, and circulate freely throughout the system, and when supplied with proper nutriment multiply by self-division and ultimately develop into cells like those from which th…

Of or pertaining to the chin and hyoid bone; as, the geniohyoid muscle.

A loose hydrated form of silica, a variety of opal, deposited in concretionary cauliflowerlike masses, around some hot springs and geysers.

Characteristic of a ghoul; vampirelike; hyenalike.

Any arboreal ape of the genus Hylobates, of which many species and varieties inhabit the East Indies and Southern Asia. They are tailless and without cheek pouches, and have very long arms, adapted for climbing.

A hydrate of alumina.

A native hydrated silicate of alumina, lime, and potash, first noticed near Rome.

red large portions of the northern hemisphere to the mountain tops. -- Glacial theory or hypothesis. (Geol.) See Glacier theory, under Glacier.

A remarkable vitreous sponge, of the genus Hyalonema, first brought from Japan. It has a long stem, consisting of a bundle of long and large, glassy, siliceous fibers, twisted together.

A siliceous sponge, of the genus Hyalonema, and allied genera; -- so called from their glassy fibers or spicules; -- called also vitreous sponge. See Glass-rope, and Euplectella.

green mineral characteristic of the greensand of the chalk and other formations. It is a hydrous silicate of iron and potash. See Greensand.

The tongue, or lingua, of an insect. See Hymenoptera.

Pertaining to both the hyoidean arch and the tongue; -- applied to the anterior segment of the hyoidean arch in many fishes. -- n. The glossohyal bone or cartilage; lingual bone; entoglossal bone.

n organic acid, obtained by the partial oxidation of glycerin, as a thick liquid. It is a hydroxyl derivative of propionic acid, and has both acid and alcoholic properties.

ine, nitrogenous substance, with a sweet taste, formed from hippuric acid by boiling with hydrochloric acid, and present in bile united with cholic acid. It is also formed from gelatin by decomposition with acids. Chemically, it is amido-acetic acid. Called also glycin, and glycocin.

arly in the embryo. It is quickly changed into sugar when boiled with dilute sulphuric or hydrochloric acid, and also by the action of amylolytic ferments.