EPI 



EPI 



passed a whole lunation, and about three 

 days more. The age of the moon (thus 

 varying) on the first day of any year is 

 termed the Epact. 



EPI- (67rt)- A Greek preposition, with 

 the radical signification of upon ; hut de- 

 noting also, in some compounds, over, all 

 through, besides. 



1. Ep-agomincp (kna'foij.evai rj^uepa/, in- 

 tercalated days). A term applied to the 

 five days which were added by the Egyp- 

 tians to their calendar at the end of each 

 year, to complete the number of 365. 

 At the end of every fourth year, a sixth 

 epagomene was added, to remedy the in- 

 convenience arising from the six hours 

 still remaining at the completion of every 

 year. 



2. Epi-genesis (yei/eo-t?, generation). A 

 term applied to a theory of non-sexual 

 generation, in which each new germ is 

 an entirely new production of the parent 

 organism. See Evolution. 



3. Ep-hemeridce {h/J^epa, a day). A 

 group of Neuropterous insects, named 

 from the ephemera, or day-fly, which are 

 aquatic in their preparatory states, and 

 emerge from the water to undergo their 

 final metamorphosis. The ephemera is 

 so named from its last stage of existence 

 being generally limited to twenty-four 

 hours. 



4. Ep-hemeris (rjjuepa, a day). A term 

 applied to an astronomical table or al- 

 manac which assigns the place of a planet 

 for a number of successive days. 



5. Epi-blastus {^Xaaro^, germen, a 

 shoot). A term applied by Richard to a 

 peculiar appendage which occasionally 

 occurs in the monocotyledonous embryo, 

 in the form of an anterior cotyledon. 



6. Epi-caridians (Kaptf, a shrimp). A 

 family of Tsopodous crustaceans, which 

 are parasitic upon shrimps. 



7. E pi-carp (/<ap7r6f, fruit). The ex- 

 terior portion of the pericarp, commonly 

 termed the skin of the fruit. 



8. Epi-cycle{KvK\oi, a. circle). Literally, 

 a circle upon a circle. The ancient 

 astronomers supposed that the motions 

 of the heavenly bodies must necessarily 

 be in circles : and in order to make that 

 doctrine tally with observation, they in- 

 vented, in succession, the two theories of 

 Epicycles^ and Eccentrics. In the former, 

 called also the Concentric Theory, the 

 earth was supposed to be placed in the 

 centre of a circle, on the circumference of 

 which the centre of another circle re- 

 volved; and on the circumference of this 

 second circle (called an Epicycle) the 



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planet was imagined to move : a suppo- 

 sition which accounted in some degree 

 for the apparent irregularities of its mo- 

 tion. The primary circle was called the 

 Deferent. In the Eccentric Theory, the 

 earth was also placed stationary in the 

 centre of the starry sphere ; but the sun 

 was carried round in a circle, the centre 

 of which was eccentric from that of the 

 earth. 



9. Epi-cycloid {nvKKoeidrj^, circular). 

 If a circle roll upon the circumference of 

 another circle instead of a straight line, 

 points, either on, within, or without its 

 circumference, if on the same plane, will 

 form varieties of Epicycloids. 



10. Epi-dermis {depfxa, skin). The ex- 

 ternal covering of the skin, commonly 

 called cuticle, in plants and animals. 

 Also the outer rough coating of shells, 

 over which it is spread as a fibrous horny 

 skin, though destitute of sensation. 



11. Epi-dote {8idu>iJii, to give). A sub- 

 species of prismatoidal augite, also termed 

 acanticone and pistacite, occurring in 

 primitive beds and veins. The name is 

 said to be derived from an enlargement 

 of the base of the prism in one direction, 

 the prefix here denoting besides. 



12. Epi-gene crystals {yevo?, a kind). 

 Substances found naturally crystallized 

 in a form which does not belong to them- 

 selves, but to some other compound of 

 the same base : thus, crystals of oxide of 

 iron are found with the form of sulphuret 

 or carbonate of iron. In these, it appears 

 that the crystals must have undergone a 

 chemical change, unaccompanied by 

 change of form. 



13. Epi-geous (7»j, the earth). A term 

 applied to the situation of plants, when 

 they grow close upon the earth ; and to 

 those cotyledons which emerge from the 

 ground, and assume the colour of leaves. 



14. Epi-gonium {yovrj, the seed). A 

 membranous bag which encloses the 

 conceptacle or capsule of Jungermannia, 

 and is ruptured as the latter elongates. 

 It is somewhat analogous to the calyptra 

 of Mosses, but is not carried up on the 

 summit of the capsule. 



15. Epi-gynous {yvvrj, a woman). That 

 condition of the stamens of a plant, in 

 which they adhere both to the calyx and 

 the ovarium, appearing to be inserted 

 upon the summit of the ovarium, as in 

 umbelliferous plants. 



16. Epi-meral (juepoc, a part or limb). 

 A term applied to the part of the seg- 

 ment of an articulate animal which is 

 above the joint of the limb. 



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