METAMORPHOSES OF ANIMALS. 



109 



Lamellibr'ancHata seems to be very uniform, but they 

 differ greatly as to their breeding, many laying their eggs 

 before the germ is formed, whilst others carry them in 

 their gills until the young are entirely formed. 1 This is 

 observed particularly among the Unios, some of which, 

 however, lay their eggs very early, while others carry them, 

 for a longer or a shorter time, in a special pouch of the 

 outer gill, which presents the most diversified forms in 



les Anim. sans Vertebres, etc. q. a. 

 CHAMISSO, (Ao. v.,) De animalibus 

 quibusdam e classe Vermium Lin- 

 nteana. Fasc. 1, De Salpa, Berol. 

 1819, 4to. } fig. MEYEN, (F. J.,) Bei- 

 trage zur Zoologie, etc., 1st Abth., 

 iiber Salpen, Nov. Act. Nat. Cur. 

 1832, vol. 16. EDWARDS, (H.MiLNE-) 

 Observations sur les Ascidies corn- 

 posees des cotes de la Manche ; Paris, 

 1841, 4to., fig. SAKS, (M.,) Beskri- 

 velser, q. a. Fauna litt., q. a, 

 VAN BENEDEN, (P. J.,) Recherches 

 sur 1'embryogenie, I'anator0ie et la 

 physiologic des Ascidies simples, 

 Mem. Ac. Brux., 1847, vol. 20. 

 KROHN, (A.,) Ueber die Entwickel- 

 ung der Ascidien, Miiller's Arch., 

 1852, p. 312. KOLLIKER, (A.,) et 

 LOWIG, De la composition et de la 

 structure des enveloppes des Tuni- 

 ciers, Ann. Sc. Nat. 3e ser., vol. 5, p. 

 193. HUXLEY (Tn. H.), Observa- 

 tions upon the Anatomy and Physi- 

 ology of Salpa and Pyrosoma, Philos. 

 Trans. R. Soc., 1851, II., p. 567. 

 ESCHBICHT (D. F.), Anatoinisk-phy- 

 siologiske Undersogelser over Sal- 

 perne, Kiob. 1840, fig. STEENSTRUP, 

 (J.,) Ueber den Generationswechsel, 

 q. a. VOGT (C.), Bilder aus dem 

 Thierleben, Frankfurt a. M., 1852, 

 8vo. MULLER (H.), Ueber Salpen, 

 Zeitsch. f., wiss., Zool., vol. 4, p. 329. 

 LEUCKART (R.),ZoologischeUnter- 

 suchungen, Giessen, 1853-54, 4to., 

 fig., 2d Fasc. GEGENBAUER (C.), 

 Ueber die Entwickelung von Dolio- 

 lum, &c., q. a., p. 104. 



1 CARUS (C. G.), Entwickelungs- 

 geschichte unserer Flussmuschel, 



Leipzig, 1832, 4to., fig. QUATRE- 

 PAGES (ARM. DE,), Sur 1'embryogenie 

 des Tarets, Ann. Sc. Nat., 3e ser., 

 1849, vol. 2, p. 202. Sur la vie in- 

 terbranchiale des petites Anodontes, 

 Ann. Sc. Nat., 2de ser., vol. 5, p. 321. 

 LOVEN (S. L.), Om Utvecklingen 

 of Mollusca Acephala, Overs. Vet. 

 Akad. Forhandl. ; Stockholm, 1849. 

 Germ. Miiller's Arch., 1848, p. 531, 

 and Wiegman's Arch., 1849, p. 312. 

 PREVOST, (J. L.,) De la generation 

 chez la rnoule des peintres, Mem. Soc. 

 Phys. ; Geneve, 1825, vol. 3, p. 121. 

 VOGT, (C.,) Bilder aus dern Thierle- 

 ben ; Frankfurt, 1852, 8vo. SCHMIDT, 

 (0.,) Ueber die Entwickelung von Cy- 

 clas calyculata, Drap. Muller's Arch., 

 1854, p. 428. LEYDIG, (F.,) Ueber 

 Cyclas cornea. Muller's Arch., 1855, 

 p. 47. LACA/E-DUTHIERS, (H.,) Re- 

 cherches sur les organes geuetaux des 

 Acephales lamellibranches, Ann. Sc. 

 Nat. 4e. ser., 1854, vol. 2. Meuioire 

 sur 1'organe de Bojanus des Acephales 

 lamellibranches, Ann. Sc. Nat., 4e. 

 ser., 1855, vol. 4. Observations sur 

 1'hermaphrodisme des Anodontes, 

 Ann. Sc. Nat., 4e. ser., 1855, vol. 4. 

 Memoire sur le developpeinent des 

 branchies des Mollusques Acephales 

 lamellibranches, Ann. Sc. Nat., 4e. 

 ser., 1856, vol. 5. Histoire de 1'or- 

 ganisation et du developpement du 

 Dentale, Ann. Sc. Nat., 4e. s6r., 1856, 

 vol. 6. I have not yet been able 

 to secure DAVAISNE'S paper on the 

 reproduction of the Oyster, published 

 in the Memoires de la Societe de Bio- 

 logic. 



