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hesis of Haeckel, man and all other animals, that in the first stages of their individual evolution pass through a two-layered structural stage, or gastrula form, must have descended. This idea constitutes the Gastræa theory of Haeckel. See Gastrula.

Of, pertaining to, or illustrating, the revolutions of the earth; as, a geocyclic machine.

um. -- Germ theory (Biol.), the theory that living organisms can be produced only by the evolution or development of living germs or seeds. See Biogenesis, and Abiogenesis. As applied to the origin of disease, the theory claims that the zymotic diseases are due to the rapid development and multiplication of various ba…

The Marxian socialism and programme of reform through revolution as advocated by the French political leader Jules Basile Guesde (pron. ged) (1845- ). -- Guesd"ist (#), n. & a.

In phylogeny, the evolution of distinct sexes in species previously hermaphrodite or sexless.

y. Gorge circle (Gearing), the outline of the smallest cross section of a hyperboloid of revolution. -- Gorge hook, two fishhooks, separated by a piece of lead. Knight.

, as around a fixed center; a circular or spiral motion; motion about an axis; rotation; revolution. The gyrations of an ascending balloon. De Quincey. If a burning coal be nimbly moved round in a circle, with gyrations continually repeated, the whole circle will appear like fire. Sir I. Newton.

A circular motion, or a circle described by a moving body; a turn or revolution; a circuit. Quick and more quick he spins in giddy gyres. Dryden. Still expanding and ascending gyres. Mrs. Browning.

om the erroneous idea that it was brought into America by the Hessian troops, during the Revolution.

In evolution, a deviation from the typical sequence in the formation of organs or parts.

The Hungarian army in the revolutionary war of 1848-49.

e ascendant, first house, or house of life, downward, or in the direction of the earth's revolution, the stars and planets passing through them in the reverse order every twenty- four hours.

Pertaining to, employed in, or produced by, the evolution of electricity by means of a battery in which water or steam is used. Hydro-electric machine (Physics), an apparatus invented by Sir William Armstrong of England for generating electricity by the escape of high-pressure steam from a series of jets connected with…

planes in hyperbolas; also, the solid, bounded in part by such a surface. Hyperboloid of revolution, an hyperboloid described by an hyperbola revolving about one of its axes. The surface has two separate sheets when the axis of revolution is the transverse axis, but only one when the axis of revolution is the conjugate…

n two others, to transfer motion from one to the other without changing the direction of revolution. -- In idle, in vain. [Obs.] "God saith, thou shalt not take the name of thy Lord God in idle." Chaucer.

intended certificate, issued by the government of the United States at the close of the Revolution, for the principal or interest of the public debt. D. Ramsay. A. Hamilton.

To change or alter by introducing something new; to remodel; to revolutionize. [Archaic] Burton. From his attempts upon the civil power, he proceeds to innovate God's worship. South.

In the theory of evolution: The process by which the manifold is compacted into the relatively simple and permanent. It is supposed to alternate with differentiation as an agent in development.

; the multiplication of a quantity into itself a given number of times; -- the reverse of evolution.

act, process, result of an act or a process, thing acted upon, state, or condition; as, revolution, the act or process of revolving; construction, the act or process of constructing; a thing constructed; dominion, territory ruled over; subjection, state of being subject; dejection; abstraction.