132 PARSONS Boston. For several years he was a constant contributor to the " North American Review," writing also for other periodicals, and founded and edited the "United States Literary Ga- zette." He was an early convert to the doc- trines of the New Jerusalem church, and has written much in exposition and defence of them. Three volumes of "Essays" (1845 et 8 eq. "Deus Homo" (1867), and "The Infinite and the Finite " (1872), are his chief S wedenbor- gian works. In 1847 he was appointed Dane professor of law in the Harvard law school, and he has since resided at Cambridge, occu- pying his leisure in the preparation of legal treatises. He has published " The Law of Con- tracts" (2 vols., 1853; 5th ed., 3 vols., 1864); " Elements of Mercantile Law " (1856) ; " Laws of Business for Business Men" (1857); an elaborate and comprehensive treatise on mari- time law, including the law of shipping, the law of marine insurance, and the law and prac- tice of admiralty (2 vols., 1859) ; " Notes and Bills of Exchange" (2 vols., 1862); "Law of Partnership" (1867); "Marine Insurance and General Average" (2 vols., 1868); "Shipping and Admiralty" (2 vols., 1869); and "The Political, Personal, and Property Rights of a Citizen of the United States" (1875). PARSONS, Thomas William, an American poet, born in Boston, Aug. 18, 1819. He was edu- cated at the Boston Latin school, and in 1836 visited Italy, where he studied Italian litera- ture and translated the first 10 cantos of Dante's Inferno (Boston, 1843). He took the degree of M. D. at Harvard university in 1853, and for some years practised as a dentist. In 1854 he published " Ghetto di Roma," a volume of poems. His translation of the Inferno was completed and published, with illustrations, in 1867 (4to, Boston). He resided for some years in England, but returned to Boston in 1872. His later volumes of original poems are " The Magnolia" (printed privately, 1867), " The Old House at Sudbury" (1870), and "The Shadow of the Obelisk" (London, 1872). PARSONSTOWN, or Birr, a town of King's co., Ireland, 69 m. W. S. W. of Dublin ; pop. in 1871, 4,939. It contains two national schools (one for girls and one for boys), a hospital, a reading room, and a mechanics' institute. Near it is Birr castle, the residence of the earl of Rosse, with his celebrated observatory. PARTHENOGENESIS (Gr. irapdivog, virgin, and ytveoig, birth), a name given to the phenome- non in the organic world, believed by many to occur, though still questioned by others, of a production of successive generations of pro- creating individuals, originating from a sin- gle fertilized ovum, but without any renewal, through such series, of fertilization. Ordinari- ly careful observations seem at first to result in the rule that, certainly in the animal realm, and probably in the vegetable, offspring can only arise by means of a union of sexual ele- ments, though this union may be either obvious or concealed. Yet there were those among PARTHENOGENESIS the earlier writers who held to be possible what they called a lucina sine concubitu. M. Bonnet, about the middle of the 18th century, first gave a scientific standing to this opin- ion, by discovering that the aphis (plant louse) may produce a numerous offspring, and these be followed by several generations, without the intervention in any known or conceivable way of the masculine fertilizing principle. M. de Quatrefages proposed to name this result agamogenesis, or production without union. The name at the head of this article was ap- plied to certain cases of this kind by Prof. Owen. Of Siebold's work on this subject a translation appeared in London in 1857. Strict- ly, the name parthenogenesis is hardly ap- propriate, since either the producers in these cases are not perfect ordinary females, or the production is not that of perfect ordinary off- spring ; or both these circumstances may be true. Siebold investigated this unisexual, or at least unusual generation in certain sac-bearing lepidoptera, in the silkworm moth, and in the honey bee. In the first, females only result ; in the second, both sexes. Along with Dzier- zon, he obtained in relation to the honey bee the most complete set of observations. The queen bee, impregnated once for all for her five or six years of life, deposits thereafter, at proper periods, the germs of successive swarms or colonies ; and the microscope reveals the fact that the eggs destined to become work- ers (imperfect females) and queens (perfect fe- males) are fertilized, as ordinarily, by contact or penetration of spermatozooids, while those to become drones (males) undergo no such in- fluence ; so that the production of these last is agamogenetic. In further proof, if the queen have her wings crippled from the first, so that she takes no flight, she produces only males, thus ruining the hive ; and a like result may follow the pinching or freezing of one side of her body, and also, because the spermatozooids have become exhausted, in her old age. So, rarely, the workers may without fertilization produce eggs, but those of males only. But any of these males, though all directly agamic or fatherless, can become efficient in a return to the ordinary or bisexual mode of reproduc- tion. In his more recent work (Leipsic, 1871), Siebold has continued his observations to the wasps (polistes and vespa) and several other insects, showing that the males in many are developed from unfertilized eggs. According to Von Grimm ("Academy," 1870) parthenoge- nesis occurs in the pupa state in the dipterous genus chironomus, as Wagner had previously announced in miastor ; this kind of reproduc- tion is called by Von Baer pmdogenesis. In this insect the formation of two egg-like re- productive bodies begins in the larva, but the eggs are not extruded till the pupa state is reached ; and he thinks these cases may be due to self-fecundation. Bonnet's experiments with the aphis yield, as intimated above, more curi- ous results. He carefully isolated a newly
