II KS VCII ASTS 



I IK VMS 



or in spring, and thence the flies develop in about 

 ten days. The egg is very minute, about n^tli of an 

 im-li, and pale red towards hatching. The larva or 

 maggot has a shining, oval body, white or yellow- 

 ish, \\iili a soft fleshy head and twelve segments. 



Hessian Fly (Cecidomyia destructor) : 

 m, magnified; b, natural size; c, pupa cases ('flax-seeds') in 

 different stages, natural size and magnified ; d, barley stein, 

 allowing 'flax-seeds' in situ; e, stem elbowed down. (From 

 Hiss Ormerod.) 



The mouth parts are very delicate, but near the 

 hind end is a chitinous ' anchor process,' which is 

 probably used as a digger or scraper. The pupa- 

 cases, which are called 'flax-seeds, 'are about jth of 

 an inch in length, of a long oval shape, and of a 

 brownish or chestnut colour. The fly itself is a 

 little stout-made black and brown gnat, about 

 it h of an inch in length. 



The fly was first known as a scourge in North 

 America during the years 1786 and 1789, and owes 

 its name to the erroneous supposition that it was 

 imported by the Hessian troops, mercenaries of 

 Great Britain. In England it appeared in 1788, 

 and "was described by Sir Joseph Banks. ' It is now 

 known to exist in the south of France, Austria, Hun- 

 gary, and southern Russia, and its original habitat 

 is considered most probably to have been southern 

 Europe and western Asia. In 1886 it occurred in 

 Britain, and in some districts is said to have caused 

 a loss of several bushels per acre. In some years 

 the loss in America has been enormous ; as in the 

 years 1790, 1821, 1844-45, 1871-72, 1876-78. Late 

 sowing, ' ploughing in ' infested stubble, the use of 

 1 bait patches of corn, rotation of crops, the selec- 

 tion or strong-stemmed corn, and the like are 

 suggested preventions of the scourge. 



See CECIDOMYIA, CORN INSECTS ; E. A. Ormerod, The 

 Hestian Fly (Lond. 1886); A. S. Packard, 'The Hessian 

 Fly, its ravages, &c.' in U.S.A. Third Rep. of Entomoloy. 

 Comm. ( Washinjjton, 1883) ; H. A. Hagen, 'The Hessian 

 Fly not imported from Europe,' in Canad. Entomolo- 

 gist (1880); B. Wagner, Die new Getreide GaU-Mucke 

 (1861). 



HesychastS (Gr. hesycfiazctn, ' to be quiet'), a 

 mystic and contemplative sect of the Greek Church 

 in the 14th century, who may be described as the 

 Quietists of the East. A Basilian monk, named 

 Barlaam, a native of Calabria, in the course of a 

 visit to the monasteries of Greece, observed among 

 the monks of Mount Athos several practices and 

 doctrines which he considered grievously reprehen- 

 sible, but one in especial. Believing that in tin- 

 soul lay hidden a certain divine light, which it was 

 the office of contemplation to evoke, the monks 

 withdrew at stated times to a retired place, seated 

 themselves on the earth, and fixed their eyes stead- 

 fastly on the centre of the stomach (whence the 

 soubriquet by which they were known, omplmlu- 



psychoi, ' navel HOU!H' ) ; and they averred that, after 

 the allotted time of contemplation, a kind of 

 heavenly light l"-,un.-.l forth upon them from the 

 soul (whose neat, they held, wan in that region), 

 and tilled tin-in with <-t.-t.-v and Hupernatural 

 delight. The monks were defended by Gregory 

 Palamas, the Archbishop of Theiwalonica ; ami 

 councils in 1341 and I .Til pronoueed in their 

 favour. But the public voice was hostile to the 

 sect, and they soon fell into obscurity. Bee Stein's 

 monograph ( Vienna, 1874). 



Hesycllius, a Greek grammarian of Alexandria, 

 flourished probably towards the end of the 4th cen- 

 tury A.D. He was the author of a Greek lexicon, 

 containing words and phrases, obscure, rare, and 

 dialectical, which, in spite of the corruption of the 

 text, is one of the most useful books we have for 

 understanding the works of the great classic writers 

 of Greece. The best edition is that published by 

 Albert! and Ruhnken (1746-66 ) ; with additions by 

 Schow, 1792. HESYCHIUS of Miletus wrote a work 

 on eminent Greek writers, and a universal history 

 (mostly lost) down to 518 A.D. See Orelli's edition 

 (1820). 



Hetairaf, or YIET&RM (Gr., 'female com- 

 panions'), the courtesans of Athens, who enjoyed 

 a social standing not elsewhere accorded to them, 

 were often women of high culture, and exercised 

 great influence. See ASPASIA, LAIS, PHRYNE. 



Hetairists. See YPSILANTI. 



Heterocercal (Gr. het&ros 'unequal,' and 

 kerkos, 'tail'), Agassiz' term for the tail of 

 Elasmobranch and most Ganoid fishes, in which 

 the vertebral axis is bent upwards in the tail, 

 making the upper lobe much the larger (see the 

 article STURGEON). In bony fishes also the axis is 

 somewhat bent upwards in its termination, but the 

 asymmetry is disguised, and the tail looks equal- 

 lobed or homocercal. In some Teleosteans and 

 Ganoids, in a few Elasmobranchs, and in Dipnoi, 

 the tail is genuinely symmetrical or diphycercal. 



Hcterop'oda, pelagic Gasteropods, in which 

 the ' foot ' has become a swimming organ. In 

 association with their active life on the surface of 

 the ocean must be noted not only the locomotor 

 foot, but the protective transparency, the highly- 

 developed nervous system ana sensory structures, 

 eyes, ears, and smelling organ. The toothed rib- 

 bon in the mouth is also very elaborate. Techni- 

 cally the Heteropods are included among the Azygo- 

 branchs. Atlanta, with a large visceral dome and 

 shell ; Carinaria, with a reduced hump and small 

 cap-like shell ; and Pterotrachea, without a hump or 

 shell, are the three types. See GASTEROPODA, 

 MOLLUSCS. 



Heterop'tera* a sub-order of insects including 

 Water-bugs, Water-scorpions, &c. See HEMIPTERA. 



Hetman, or ATAMAN, the title of the head or 

 general of the Cossacks (q.v.). 



Hfvelilis (whose real name was HOVEL or 

 HOVELKE), JOHANN, German astronomer, was lorn 

 at Danzig, 28th January 161 1, and died in that city, 

 28th January 1687. He was wealthy, and in 1C.41 

 he erected an observatory in his own house, and 

 for forty years carried on astronomical observations 

 therefrom. He wrote description* ol tin- phases ami 

 spots of the moon, conducted numerous researches 

 on <-<>mets, and prepared charts of the moon and of 

 the heavens. He laid down the results of liis ol>er- 

 vations in Selenographia (1647), Cometographitt 

 (1668), and Machina Cale&tis (1673; reprinted, 

 with an English trans, by Prince, in 1882), besides 

 minor works. 



Heves, a town of Hungary, 60 miles ENE. of 

 Pesth. Pop. 6698. 



