Chap. I. 



METAMORPHOSES OF ANIMALS. 



77 



still entertained respecting the genetic connection of many of the fonns which 

 appear to belong to the same organic cycle.' It is also still questionable, whether 

 Gregarinai and Psorosjjermia are embryonic forms or not, though the most recent 

 investigations render it probable that they are.^ The development of the Annu- 

 lata, as they are now circumscribed, exhibits great variety;^ .some resemble more 

 the Nematods, ui their metamorphoses, while others, the Leeches for instance. 



^ Noni>MAXN', (Al. v..) Jlicroprraphische Beilraije 

 zur Naturgeschichtc der wirbelloscn Tliiere, Bi-rlin, 

 1832, 4to. tig. — BciANUS, (L.,) Zcrkarien und ilir 

 Fumlort, Isis 1818, vol. 4, p. 720. — Enthelmin- 

 tica Isi.s 1821, p. 1G2. — C.vuus, Boobachtungon iiber 

 einen nicrkwiirdigen Eingeweidewurm, Leucoclilori- 

 dium paradoxum, Nov. Act. Ac. Nat. Cur., vol. 17, 

 p. 8.5. — SiEBOLD, (C. Tii. E. v.,) Ileliiiiiitliologisehe 

 Beitriige, Wiegman's Archiv, 1835, vol. 1, p. 45. — 

 Ueber die Conjugation des Diplozoon paradoxum, 

 etc., Zeitsch. f. wiss., Zool., 1851, vol. 3, p. 62.— 

 Gyrodactylus, ein amniendes Wesen. Zeitsch. f. wiss. 

 Zool., 1849, vol. l,p. 347. — Steexstkup, (.1.,) Ge- 

 nerationswechsel, etc., q. a. — Biliiauz, (Tii.,) Ein 

 Beitriig zur Helminthographia humana, Zeitsch. f. 

 wiss. Zool., 1852, vol. 4, p. 59. — Agassiz, (L.,) Zoo- 

 logical Notes, etc., Amer. Journ. Sc. and A. 1852, vol. 

 13, p. 425. — Baer, (K. E. v.,) Beitriige zur Kennt- 

 niss der niedern Thiere, Act. Nov. Nat. Cur. 1827, 

 vol. 13. — AuitERT, (II.,) Ueber das AVassergefiiss- 

 system, die Geschlechtsverhiiltnisse, die Eibildung 

 und die Entwickelung von Aspidogaster coneliicola, 

 Zeitsch. f. wiss. Zool. 1855, vol. fi, p. 349. — Leidy, 

 (Jos.,) Description of two new Species of Distonia, 

 witli tiie partial History of one of them, .Tour. Ac. 

 Nat. Sc. Phil. 1850, vol. 1, p. 301, fig. 



* MiJLLEn, (.T.,) Ueber eine eigenthiimliche 

 krankhaftc parasitische Bildung, etc., Miiller's 

 Archiv, 1841, p. 477. — Ueber parasitische Bildun- 

 gcn etc., Miiller's Archiv, 1842, p. 193. — Dufouk, 

 (L.,) Note sur la Gregarine, etc., Ann. Sc. Nat., 

 1828, vol. 13. p. 3GC, fig. — Ibid., 2de ser., 1837, 

 vol. 7, p. 10.— SiEBOLi), (C. Tn. E. v.,) Beitriige 

 etc., q. a.; p. 5G-71. — IlAMMEUscnMiDT, (C. Ed..) 

 Helii\inlliologischc Beitriige, Isis 18;!8, i>. 351. — 

 Kiii.i.iKEU. (A..) Die Lehre von der tliicrischen 

 Zelle, etc., Zeitsch. wiss. Botanik. 1845, vol. i.. p. 40, 



and p. 97. — Beitriige zur Kenntniss niederer Thiere, 

 Zeitsch. f. wiss. Zool. 1848, vol. i. p. 1. — IIeni.e, 

 (.1.,) Ueber die Gattung Gregarina, Miiller's Archiv, 

 1845, p. 309. — Frantzius, (Al. v.,) Observationes 

 qua;dam de Gregarinis, Berolini, 184G. — Stein, (F..) 

 Ueber die Natur der Gregarinen, Miiller':5 Archiv, 

 1848, p. 182, fig. — Brcch, (C.,) Einige Bemer- 

 kungen iiber die Gregarinen, Zeitsch. f. wiss. Zool. 

 1850, vol. 2, p. 110. — Leydk:, (F.,) Ueber Proro- 

 spermien und Gregarinen, Miiller's Archiv, 1851, 

 p. 221. — Leidt, (Jos.,) On the Organization of the 

 Genus Gregarina, Trans. Amer. Phil. Sec 1851, vol. 

 10, p. 233. — Some Observations on Neni.itoidea im- 

 perfecta and Descriptions of three parasitic Infusoria, 

 Trans. Amer. Phil. Soc. 1851, vol. 10, p. 241.— 

 LiEBERKUHN, (N.,) Ucbcr die Psorospermien, Miil- 

 ler's Archiv, 1854, p. 1. 



' Weber, (E. II.,) Ueber die Entwickelung von 

 Ilirudo medicinalis, Meckel's Archiv, 1828, p. 306, 

 fig. — FiLiPPi, (FiL. DE,) Sopra I'anatomia e lo svi- 

 luppo delle Clepsine, Pavia, 1839, 8vo. fig. — Lovex, 

 (.7.,) Beobaclitungen iiber die Metamorphose einer 

 Annelide, K. Yet. Ac. llandl. 1840, Wiegmann's 

 Arcliiv, 1842, vol. i., p. 302. -Oersted, (A. S.,) 

 Ueber die Entwickelung der Jungen bei einer Anne- 

 lide, etc., "Wiegmann's Archiv, 1845, vol. i., p. 20. — 

 Sars, (M.,) Zur Entwickelung der Anneliden, Wieg- 

 mann's Archiv. 1S|5, vol. i.. p. 11. — Menge, (A.,) 

 Zur Roth-Wiirincr Gattung Euaxes, Wiegmann's 

 Archiv, 1845, vol. i., p. 24. — Grube, (A. E..) Zur 

 Anatomic und Entwickelung der Kicmenwiirmer, 

 Konigsbcrg, 1838, 4t<). — Actinicn, Echiiiddermen und 

 AVilrmer, etc., Konigsberg, 1840, 4to. fig. — Unter- 

 suchungen iiber die f'ntwickelung der Clepsine, Dor- 

 pat, 1844. — Edwards, (II. Mii.ne.) Observations 

 sur le d(''V<'l<>piieincMt des Aiiiieliiles. Ann. Se. Xat. 

 3e ser. 1845, vol. 3, p. 145. — Kocii. (H..) Einige 



