LITERATURE. 83 



that the origin of the efferent genital ducts is to be traced to the nephridia 

 and that they only gradually became separated from these latter organs. 

 Among the Lamellibranchs, processes may have taken place similar to those 

 in certain Annelida (Capitellidat), in which new ducts are developed out of the 

 nephridia for the genital products. Such a modification of the nephridia 

 which originally served for conducting the genital products would be explicable 

 as a consequence of the modified function of the coelom and the shifting of 

 the genital glands thus brought about.* 



LITERATURE. 



1. BARROIS, TH. Note sur I'embryogenie de la Moule commune 



(My til us edulis). Bull. sci. Nord Franc*, (ii.) 2 annee 

 (18791). 



2. BARROIS, TH. Le stylet cristallin des Lamellibranches. Revue 



!,!<,!. Xurn Fr<itHv. Tom. i. 1889. 



3. BLOCHMANN, F. Eine freischwimmende Muschellarve im siissen 



Wasser. BioL CentraJM. Bd. xi. 1891. 



4. BRAUN, M. Postembryonale Entwicklung von Anodonta. Zool. 



An?:. Jahrg. i. 1878. 



5. BRAUN, M. Die postembryonale Entwicklung der Najaden. 



Nwlu'ii'ltttbl. Deuhchen Malakozool. Gesellsch. Frankfurt a. M. 

 Jahrg. xix. 1887. 



6. BROOKS, W. K. The development of the oyster. Studies Biol. 



I. alt. Johns Hopkins Unw., Baltimore. Vol. i. 1880. 



7. BUTSCHLI, 0. Notiz zur Morphologic des Auges der Muscheln. 



Ft'.4<-ltrift naturhi#t.-med. Vereins Heidelberg. 1886 



8. CARRIERE, J. Die embryonale Byssusdriise von Anodonta. 



Zool. Anz. Bd. vii. 1884. 



9. CARRIERE, J. Ueber Molluskenaugen. Archiv. f. mikro. Anat. 



Bd. xxxiii. 1889. 



10. DALL, W. H. Report on the Mollusca (collected by the U. S. 



Steamer Blake). Bull. Mus. Comp. Zool. Harvard. Vol. 

 xviii. 1889. 



11. EHRENBAUM, E. Untersuchungen liber die Structur und Bil- 



dung der Schale der in der Kieler Bucht haufiger vorkom- 

 menden Muscheln. Zeitschr. f. wiss. Zool. Bd. xli. 1885. 



* A summary of these points which have been established chiefly by LACAZE- 

 DUTHIEBS and v. JHERING will be found in No. 24, by the last-named author, 

 as well as in BBONN'S Klassen und Ordnungen der Thierreichs, Bd. iii., Abth. 

 i. PELSENEER has also recently given an account of these conditions. 



