534 A. M. (JARK SAUNDEKS AND MAIUJAKET I'OOLK. 



from the earliest stage in the formation of the lattei-, and 

 persists as the reuo-pericardial a])erture in the adult of all 

 Molluscs with tlie exception of Nautilus. Now in Aplysia 

 there is never any connection between the c(jol()iri and the 

 secondary kidney ; there is no reno-pericardial duct in con- 

 nection with it ; the two organs, Vjoth in origin and later 

 development, are perfectly distinct. We consider it therefore 

 probable that the secondary kiduey of Aplysia is a larval 

 organ which degenerates and disappears during the meta- 

 morphosis, and that the definitive kidney arises as an evagi- 

 nation of the ccelomic epithelium as it does in Physa. 



LlS'l' OF WoKKS KKFKI!HKI) TO IN THK ThXI'.^ 



1. Barl)ieri, C. — "Forme larvati del Cyclostoma elegans," ' Zool. 



Anz.; Bd. xxxii, 19D8, p. 257. 



2. Blocliiiiaiui, F. — " Beitriige zur Kenntuiss der Entwickhmg l^ei 



Gastropodeii." ' Zeit. f. wiss. Zool.," Bd. xxxviii, 1883, p. 392. 

 8. Bourne. G. C. — " Contrilmtions to the Moi-jihology of tlie Group 

 Neritacea." ' Proc. Zool. Soc." Ut(i8 (2). p. 8l<». 



4. Carazzi. D. — " L'embriologia dell'Aplysia liraacina. L.." 'Auat. 



Anz.," Bd. xvii, 1900, p. 77. 



5. "L'embriologia dellAplysia," Archiv Ital. di Anat. e 



Enibriol.,' vol. iv. 1905. 



6. Casteeh D. B. — " Cell Lineage and Early Larval Development of 



Fiona marina."' 'Proc. Acad. Xat. Sci. Phil." vol. hi, 1904. 



7. Erlanger, R. von. — " Beitriige zur Entwicklungsgeschiclite der 



Gastropoden."" 'Mittli. Zool. Stat. z. Neapel.." Bd. x. 1892. p. 375. 



8. Glaser. O. C. — ' Correlation in the Development of Fasciolaria,"' 



'Biol. Bull." vol. X. 1906. 



9. Heath. H. — " Development of Ischnochiton."" ' Zool. Jahrb. Al>t. f. 



Anat.," Bd. xii, 1899. p. 567. 



10. Heymons. R. — 'Zur Entwicklungsgeschiclite von Umbrella 



mediterranea," ' Zeit. f. wiss. Zool.," Bd. Ivi, 1893, p. 245. 



11. Holmes. S. >^ . — '"Early Development of Planorbis,"" ' Jouni. Morpli.." 



vol. xvi. 1900, p. 369. 



' For a complete bibliography of the whole sui)ject the reader is 

 referred to Mazzarelli"s monograph (14) for list of literature up to 1892, 

 and to Cai-azzi's paper (5) for more recent work up to 1906. 



